tkc8800

Technology and retro computer blog

The ME2700 Orphan EPROM programmer

Over the last few years I've been looking for a modern and reasonably priced EPROM programmer to program early 2708 EPROMs.  2708's are used in the Cromemco 8k Bytesaver which is an early S100 PROM board that I use in my Altair 8800.  The Bytesaver itself can program 2708's, however I've never been able to get mine to do this reliably.  Most likely due to my Altair's ageing power supply.  So I need an external programmer to write EPROMS.

Up until now, I haven't been able to find such a programmer.  Most modern programmers don't support 2708's because of the odd voltages required for programming.  A work around I've used is to substitute 2708's with 2716's using an adapter (see that post here).  This made my Bytesaver board usable as 2716's are still widely supported by low cost programmers.  But I've always wanted to use the original 2708's in my Bytesaver.

Luckily such a programmer has now been developed.  Martin Eberhard recently developed the ME2700 Orphan EPROM Programmer which can program many old EPROMS including 2708's.  The ME2700 was made available through the Altair Yahoo group.  There was a limited supply of assembled units, and it was also made available as a kit.  I chose to get one as a kit.

The ME2700 kit contained the PCB, power supply and the chip containing the custom terminal software required to use the programmer.  The remaining parts were ordered through Digikey using a pre-defined parts list.  This made the process or getting all the required components quite easy.

I've been sitting on this kit for about six months, so I thought it was high time to have a go at assembling it.  I only have basic soldering and hardware diagnostic skills so I've been a little apprehensive to build the kit, as I've never soldered anything together with so many components.  This was partly the reason it took me so long to do it.  In preparation for building the kit I purchased a Hakko FX888D soldering station.  This is a medium level soldering station recommended for hobbyists.  I wanted to buy a decent soldering station to improve my chances of success with this kit.  It's also useful for my other retro machines as many of those need soldering work.

Workbench preparation
Workbench preparation
ME2700 bare PCB
ME2700 bare PCB

A PDF manual made available with the kit had excellent assembly instructions which I followed.  The first part of the assembly process was to place all the resistors and diodes onto the board, followed by all the chip sockets.  Being fairly inexperienced with electronics I triple checked the placement and orientation of all the components.  I knew I'd be better off getting things right the first time round rather than having to diagnose and repair.

Resistors and diodes installed
Resistors and diodes installed
Sockets installed
Sockets installed

The next part of the process was to add all of the other small components.  And then gradually adding the larger components until the board was complete.  Prior to installing any IC's onto the board a voltage check needed to be performed to ensure none of the IC's would be damaged by incorrect voltages.  I'm happy to say all the voltage checks succeeded first time.

Assembly complete
Assembly complete

Once the IC's were in place it was time to connect the ME2700 to my PC via serial link.  I have a couple of USB to serial adapters that I use, so I connected one to my PC and after checking all the settings I turned the ME2700 on and was greeted with the software banner!  I tested options in the software all seems to be working great.  I also tested reading in a couple of EPROM types and that worked fine as well.

ME2700 connected to pc
ME2700 connected to pc
ME2700 serial software
ME2700 serial software


Since the release of the ME2700 there is a firmware upgrade which adds a couple of features, so I'll look at doing this and in the next few days I'll look at writing to some 2708's.

2708 EPROMs
2708 EPROMs


Compaq Portable II new video and sound card

I recently received the replacement video board for my Compaq Portable II and I'm glad to say it worked perfectly.  See my previous post about the CPII here.  The board is Assy. No. 000525 which is a later board than what was in the machine, but it's an appropriate board for the Portable II.  There's much fewer components on this board and many of the components are surface mounted. It's great to have the internal CRT working again.


Working internal CRT
Working internal CRT
VDU Assy no 000525
VDU Assy no 000525

The Compaq Portable II is great for running CGA games, so I decided to get a sound card for it.  I managed to get hold of a Sound Blaster Vibra 16 CT4180.   This is the cheaper plug and play version of the Sound Blaster range, but it worked out well.  These cards also have a game port connector for connecting a 15 pin joystick, so needless to say I've got one of those coming as well.

I purchased the Vibra 16 not really knowing whether it would work on a 286 machine.  It’s a 16 bit board and I’ve got a spare 16 bit slot in the CPII, so I figured I'd work it out once it arrived.  Getting the sound card working in DOS took a bit of effort but I got it working.  The Vibra 16 is a PNP card designed for later machines than a 286.  So at first when I tried to install the drivers the card wasn't detected and running the Sound Blaster configuration manager would lock up the machine.


creative vibra 16 ct4180
SB Vibra 16 CT4180
creative vibra 16 ct4180 connectors
Vibra 16 ports
Compaq Portable II cards
Video & sound cards installed

In doing some research on the web I discovered a utility called EMU386 which is a driver that will emulate 386 opcodes on a 286.  The Vibra 16 software must use some 386 opcodes and therefore requires EMU386 to install properly. Once Emu386 was installed, I then installed the Sound Blaster basic drivers and the Sound Blaster Configuration Manager.  These two installs made all the necessary changes to the autoexec.bat and config.sys files and once I restarted the sound card worked.


Vibra16 sound card detected
Sound card detected
Compq Portable II ports
CPII card ports

While I was at it, I also installed MSDOS 6.22.  This took a bit of effort because I don’t have a 1.44 floppy connected to the machine, it only has the 360k floppy drive.  I didn’t like the prospect of creating 360k install disks for DOS 6.22, so I looked for another solution.  I’ve got a DOS 6.22 360k boot disk, so I used that to format the hard drive with the system files:

A:>format /s/q

This does a quick format of the hard drive and installs the system files required for a hard drive boot. Once that was done I simply removed the CF hard drive and connected it to my Windows pc.  I then manually created the DOS folder and copied the DOS files from my PC.

Here’s a video of the Compaq Portable II with Sound Blaster Vibra 16 running Prince of Persia, the sound is really impressive.





Downloads

See below for EMU386, Sound Bster Vibra 16 DOS drivers and the DOS 6.22 CD image.

DOS6.22_CD.iso.zip (1.79 mb)

EMU386_em3134b1.zip (18.15 kb)

sbbasic.zip (1.15 mb)

ctcmbbs.zip (671.25 kb)


Compaq Portable II Restoration

I recently acquired a Compaq Portable II.  It was great to get hold of this machine because I have the Compaq Portable I and III, so this completed the set.  This machine was somewhat of a basket case, the video board was defective and was preventing it from starting.  Initially on power up there was a beep and a red flashing light on the front.  The seller was good enough to diagnose this before I bought the machine and supplied a replacement IBM EGA (IBM 6278173XM), board to get the machine running.  The EGA board allows the machine to start up but it doesn't have the connector to drive the internal CRT, so you have to use an external monitor.  The 360k 5.25” floppy drive in the machine worked but the door was very sticky and wouldn’t open or eject disks properly, but luckily it read disks fine.


IBM-6278173XM_EGA_board.jpg
IBM 6278173XM EGA board


Another problem was that the hard drive only worked once the machine warmed up.  This is a classic case of "sticktion" where the head is stuck from being inactive for many years.  The hard drive is the original 20mb MFM drive (type 2).  It has the MFM to IDE converter board attached to the bottom, so it's a great piece to have, but considering the reliability issues the plan was to replace it with a later model IDE drive or CF IDE adapter.  At least when the machine was booting from the hard drive it was evident that everything was working.



The defective GA2 video board


Onto disassembling the machine to get to the drives and boards.  I found a copy of the Compaq Portable II service manual online which had directions on how to disassemble the machine.  Disassembly of this machine is quite different to the Compaq Portable I, I had to refer to the manual to work it out.

Compaq Portable II - Maintenance and Service Guide.pdf



One of the first tasks was to remove the floppy drive and service the eject mechanism.  I used some lithium grease on the hinges and on the head mechanism.  The heads also got a clean with a cotton bud.  This got the eject mechanism working smoothly.


In order to test the internal CRT the video board from my Compaq Portable I was installed.  The connector for the internal CRT is the same on both machines.  Connecting the internal CRT cable required some re-routing through the case, as the connector is at the other end of the board.  Once connected the internal CRT worked fine.  The picture geometry and brightness were all really good.  The video board from the Compaq Portable I works in this machine but it’s considerably taller and protrudes out of top so you can’t get the case back on.  So it’s only a temporary fix.




Now that the internal CRT had tested successfully it motivated me to get a replacement video board.  A search on U.S Ebay found several Compaq Portable video boards for sale, but they were rather expensive considering I have to pay international postage and exchange rates.  I found a listing for a later model video board (Assy no. 000525) for a reasonable price so I bought it.  This video board is listed in the Compaq Portable II technical manual as an option so it’s an appropriate replacement.


Having sorted out the video issue for now my focus shifted to replacing the hard drive.  I have several newer IDE drives but they’re all fairly large by the standard of the Compaq Portable II.  The smallest I have is 40gig.  The Compaq Portable II setup disk only caters for a selection of specific drives and none are anywhere near that capacity.  I’ve read that these larger drives can be used with the assistance of a BIOS overlay which is specific to the drive’s brand.  I instead decided to try using a compact flash IDE adapter that I have.  Trying several hard drive types using the Compaq Setup utility, I eventually succeeded with the 20mb type 2 hard drive option.  The CF card in use was 1gig, so it wasn’t a very good  use of its capacity.  I have a couple of smaller CF cards that are closer in capacity to those in the setup utility, so I’ll try to get one of those working later, but at least for now the 1gig card works.



With the convenience of having the CF hard drive working I was able to easily copy some applications over to the Compaq Portable II.  I loaded up several games and installed Windows 3.  I also plugged in a serial mouse to use with Windows, everything worked fine.



The machine has several extra boards installed, an Analogue Devices CT-180 which is an analogue to digital controller board.  It also has an SMC network card.


SMC_8_bit_network_board.jpg
SMC network card
Analogue_Devices_CT-180.jpg
Analogue Devices CT-180

Update: I've now managed to get a 160mb CF card working as a type 25, 134.5mb hard drive.  So only around 25mb of this  card is lost.  After using the DISKINIT utility on the Compaq setup disk I could see this CF card as the C: drive, but I couldn't boot from it.  On restart with boot floppy removed, the system would just stop booting with a blinking cursor in the top left of the screen.  I fixed this by running the following command:

A:\FDISK /MBR

This fixes the master boot record of the disk (CF card).  Once that was done the machine now boots from this CF card fine.




Compaq Portable II post 2:

New video card and sound card for Compaq Portable II

Floppy Emu disk archiving on Mac LC475

Recently I wanted to update my 400k Macintosh disk archive so that the .dsk files I was providing could easily be used on an old  Macintosh.  The .dsk files that I have can be used in MiniVmac and also in the Floppy Emu disk emulator, but they aren't easily usable when copied directly to an old Macintosh.  The .dsk versions have lost the Macintosh resource fork required by old Mac systems to associate the files with an application.  So I needed to come up with a method to restore them back to Macintosh images and preserve the resource fork.



I came up with the idea of connecting the Floppy Emu to my LC475 as the internal disk drive and then archiving each disk using DiskCopy 4.2.  The LC475 runs System 7.5 and has all the necessary utilities installed: Stuffit Deluxe 4, DiskCopy4.2 and DropStuff.

This process worked well.  I loaded all the .dsk images onto an SD card in the Floppy Emu, then one by one I "inserted" them into the LC475.  As far as the LC475 was concerned a physical floppy had been inserted.  I then used DiskCopy 4.2 to read each disk and save the image file to the hard drive.  Once archived to the LC475 hard drive the .image files contained the resource fork to associate them with DiskCopy 4.2.

While they exist on a Mac drive, the .image files will retain the resource fork, but once copied to a non Mac system the resource fork is lost.  The typical way of preserving the resource fork is to archive the files using Stuffit and Binhex.  Newer versions of Stuffit that run on System 7.x will generally open any file, but older versions that run on System 6 and prior will not recognise a file unless the resource fork is in tact.  So to make these files usable on System 6 machines you need to archive the Stuffit files with BinHex which preserves the resource fork in a .hqx archive.  The Bixhex archive (.hqx or .bin) can be opened by BinHex on System 6 machines without the resource fork in tact.  To make the process easier I decided to archive the images as self extracting Stuffit archives (.sea) prior to archiving with BinHex.  This means that only BinHex is required on a System 6 machine to use the archives.  Once extracted from the .hqx archive using BinHex the .sea archives can be run to extract the .image files. 

Once all .dsk images had been created on the LC475 using DiskCopy 4.2, I used DropStuff to create the individual .sea.hqx archives.  DropStuff can be configured to automatically create .sea.hqx archives.  Once configured you drag and drop multiple files onto the DropStuff icon and it does the rest.

See pictures of the process below.



The Macintosh LC475. This is a great machine for the retro Mac hobby, the cover unclips from the back and all the main components are easily accessible.  The hard drive and the floppy drive unclip and and can be removed in seconds. This machine also has a PDS Ethernet card and a reasonable sized hard drive which makes it great for transferring files via ftp.




The picture above shows the Floppy Emu connected to the LC475 as the internal floppy drive.  All I've done here is detach the cable from the internal floppy from the logic board and replace it with the cable from the Floppy Emu.



Once the Floppy Emu is connected you select a disk image and it appears on the Mac desktop just like a disk inserted into the internal floppy drive.



This picture shows the emulated floppy disk being read by DiskCopy 4.2.  Once read it can be saved as a disk image to the hard drive.

Go to the updated Mac 400k disk image page to download images.

Macintosh 128k - 512k 400k disk images

Macintosh 400k disk images

This page is dedicated to software that will run on the earliest Macintosh computers, the 128k and 512k.  All the software below has been tested on a Mac 512k with 400k floppy drive, running System 2.0 and Finder 4.1. 

I've provided these disk images in two formats: .dsk and .sea.hqx.  The .dsk files can be used in Mini vMac or in the Floppy Emu disk emulator.  The .sea.hqx files are for downloading straight to a retro Macintosh.  You'll need BixHex at a minimum on older systems to unpack the hqx archive.  Then the disk images can be extracted by running the .sea (self extracting archives).

 While there are dozens of applications for the original Macintosh on the web, I've been selective with the software below.  I've selected software that showcases these machines and still holds some interest value to today's user.  Let's face it, text adventures were good once upon a time, but I can't imagine sitting down and playing one today!

 

Apps

Data Flow flowchart application (1984)

Flowcharting application.

Download:

ZIP: DataFlow.zip

HQX: DataFlow.image.sea.hqx

Mac Write 2.0

Mac Write 2.0 (1985)

Download:

ZIP: Disk_Write_2.zip

HQX: Disk_Write_2.image.sea.hqx

MacBasic (1984)

The original MacBasic which was never released. It was replaced by MS Basic.

Download:

ZIP: MacBASIC.335.dsk.zip

HQX: MacBASIC.335.image.sea.hqx

Mac Draft 1.2a (1986)

Drafting application

Download:

ZIP: MacDraft1-2a.zip

HQX: MacDraft1-2a.image.sea.hqx

MacPaint 1.0 (1983)

The original MacPaint that shipped with the Mac 128k

Download:

ZIP: MacPaint.zip

HQX: MacPaint.image.sea.hqx

MacWrite 1.0 (1983)

The original MacWrite that shipped with the Mac 128k

Download:

ZIP: MacWrite.zip

HQX: MacWrite.image.sea.hqx

Microsoft Chart 1.0 (1984)

Charting application.

Download:

ZIP: Microsoft_Chart_1.zip

HQX: Microsoft_Chart_1.image.sea.hqx

Microsoft Basic v1 (1983)

The infamous Microsoft Basic for the Macintosh

Download:

ZIP: MSBASIC_1.zip

HQX: MSBASIC_1.image.sea.hqx

Microsoft Basic v2

Microsoft Basic v2

Download:

ZIP: MSBASIC_2.zip

HQX: MSBASIC_2.image.sea.hqx

Microsoft Basic v3

Microsoft Basic v3

Download:

ZIP: MSBASIC_3_disk1.zip

HQX: MSBASIC_3_disk1.sea.hqx

Microsoft Multiplan 1.11 English (1985)

Microsoft Multiplan spreadsheet application. The predecessor to Excel. This English version was hard to find.

Download:

ZIP: MSMultiplan_1.11.dsk.zip

HQX: MSMultiplan_1.11.image.sea.hqx

Mac Paint 2.0

Mac Paint 2.0

MacPaint version 2

Download:

ZIP: Paint_2.zip

HQX: Paint_2.image.sea.hqx

Picture Base 1.1 (1986)

Application for storing pictures.

Download:

ZIP: PictureBasev1.1.1.dsk.zip

HQX: PictureBasev1.1.1.image.sea.hqx

Games

Airborne! (1984)

Arcade game

Download:

ZIP: Airborne!.zip

HQX: Airborne!.image.sea.hqx

Brickles v7.0

A great breakout game, like the old Arkanoid.

Download:

ZIP: Brickles7.0.dsk.zip

HQX: Brickles7.0.image.sea.hqx

Cairo Shootout (1987)

Arcade game.

Download:

ZIP: Cairo_ShootOut.zip

HQX: Cairo_Shootout.image.sea.hqx

Microsoft Flight Simulator (1986)

Flight simulator

Download:

ZIP: Flight_Simulato102.zip

HQX: Flight_Simulato102.image.sea.hqx

Fokker Triplane (1985)

Flight simulator.

Download:

ZIP: Fokker_Triplane.zip

HQX: Fokker_Triplane.image.sea.hqx

Frogger (1984)

The classic arcade game Frogger. Requires direct booting from the disk.

Download:

ZIP: Frogger.zip

HQX: Frogger.image.sit.hqx

Fusillade (1985)

A grid style arcade game.

Download:

ZIP: Fusillade.zip

HQX: Fusillade.image.sea.hqx

Gemstone Warrior (1986)

An adventure game.

Download:

ZIP: Gemstone_Warrior.zip

HQX: Gemstone_Warrior.image.sea.hqx

Grid Wars (1985)

Arcade game.

Download:

ZIP: Grid_Wars.zip

HQX: Grid_Wars.image.sea.hqx

Klondike v4.0 (1989)

A really good Solitare game.

Download:

ZIP: Klondike_4.0.dsk.zip

HQX: Klondike_4.0.image.sea.hqx

Lode Runner (1983, 1984)

A great version of the classic Lode Runner.

Download:

ZIP: Lode_Runner.zip

HQX: Lode_Runner.image.sea.hqx

MacAttack (tank) (1984)

3D arcade game.

Download:

ZIP: MacAttack-v1_4.zip

HQX: MacAttack-v1_4.image.sea.hqx

MacCommand (1985)

A decent missle command clone.

Download:

ZIP: MacCommand_boot.zip

HQX: MacCommand.image.sea.hqx

MacJack_v3.0.1 (1984)

A decent Blackjack game.

Download:

ZIP: MacJack_3.0.1.dsk.zip

HQX: MacJack 3.0.1.image.sea.hqx

MacLanding (1986)

A clone of the old Defender arcade game.

Download:

ZIP: MacLanding.zip

HQX: MacLanding.image.sea.hqx

MacMan v1.0 (1986)

A great Pacman clone. You play as a Mac being chased by IBM pc's.

Download:

ZIP: MacMan_1.0.dsk.zip

HQX: MacMan_1.0.image.sea.hqx

MacMissles (1985)

A decent clone of the old Missle Command game.

Download:

ZIP: MacMissles.zip

HQX: MacMissles.image.sea.hqx

Phraze Craze (1986)

Wheel of fortune game.

Download:

ZIP: Phraze_Craze.zip

HQX: Phrase_Craze.image.sea.hqx

Psion Chess

A good looking chess game.

Download:

ZIP: Psion_Chess.zip

HQX: Psion_Chess.image.sea.hqx

Pyramid of Peril v1 EN (1985)

First person adventure game with line graphics!

Download:

ZIP: Pyramid_of_Peril_v1.zip

HQX: Pyramid_of_Peril_v1.image.sea.hqx

Rogue (1985)

The famous top view role playing adventure scroller which coined the phrase "Roguelikes".

Download:

ZIP: Rogue.zip

HQX: Rogue.image.hqx

Run for the Money (1984)

Simulation game

Download:

ZIP: Run_for_the_Money.zip

HQX: Run_for_the_Money.image.sea.hqx

ShufflePuck

Arcade game, based on air hockey.

Download:

ZIP: Shuffle_Puck.zip

HQX: Shuffle_Puck.image.sea.hqx

Sierra Boxing (1985)

Arcade style boxing game. Note: this game did not fit on a 400k disk with the system folder, so this disk image is not bootable.

Download:

ZIP: Sierra_Boxing.zip

HQX: Sierra_Boxing.sea.hqx

Social Climber

Arcade game with stupid premise. It was the 80's.

Download:

ZIP: Social_Climber.zip

HQX: Social_Climber.image.sea.hqx

Space Invaders (1985)

The classic arcade game.

Download:

ZIP: Space_Invaders.zip

HQX: Space_Invaders.image.sea.hqx

Wizard's Fire

A great arcade game, based on the old missle command.

Download:

ZIP: Wizard's_Fire.zip

HQX: Wizard's_Fire.image.sea.hqx

System

BinHex 5.0 (1985)

BixHex utility, archives files to preserve resource fork.

Download:

ZIP: BinHex_5.0.dsk.zip

HQX: BinHex_5.0.image.sea.hqx

CopyRom 512k

CopyRom 512k

Utility to extract rom from physical Mac. Rom can then be used in emulators like Mini vMac.

Download:

ZIP: CopyRom512k.zip

HQX: CopyRom512k.image.sea.hqx

Mac Speak speech synthesizer (1984)

Speech emulator. This was the one used in the famous Macintosh (128k) launch video by Steve Jobs. The Mac used in the video by Jobs had 512k of ram, four times more than a retail Mac!

Download:

ZIP: MacSpeak.zip

HQX: MacSpeak.image.sea.hqx

MacTerminal 1.1 (1984)

Early terminal program with xmodem transfers, very small around 90k.

Download:

ZIP: MacTerminal_1.1.dsk.zip

HQX: MacTerminal_1.1.image.sea.hqx

MacTerminal 2.2

MacTerminal 2.2 (1987)

v2.2 of MacTerminal, slightly bigger but has some added features.

Download:

ZIP: MacTerminal_2.2.dsk.zip

HQX: MacTerminal_2.2.image.sea.hqx

MacTerminal_Binhex5_boot disk (1983)

400k boot disk with required utilities for serial cable transfers. Contains MacTerminal 1.1 with xmodem, BinHex 5.0 and Packit 1.0

Download:

ZIP: MacTerminal_Binhex5_BOOT.zip

HQX: MacTerminal_Binhex5_BOOT.image.sea.hqx

Mac Tools (1984)

File and folder utility.

Download:

ZIP: MacTools.zip

HQX: MacTools.image.sea.hqx

Packit v1, v3

Packit v1, v3 (1985)

Packit archive utility, very small application, multiple files support, preserves resource fork of files.

Download:

ZIP: Packit.zip

HQX: Packit.image.sea.hqx

Red Ryder (1986)

Serial terminal program.

Download:

ZIP: RedRyder.zip

HQX: RedRyder.image.sea.hqx

Smooth Talker (1986)

Speech synthesiser application.

Download:

ZIP: SmoothTalker_2.1.dsk.zip

HQX: SmoothTalker_2.1.image.sea.hqx

Switcher_Multiple_Versions (1985)

The famous switcher application, allows you to switch between applications.

Download:

ZIP: Switcher_Multiple_Versions.zip

HQX: Switcher_Multiple_Versions.image.sea.hqx

System 2.0

System 2.0 (1985)

Macintosh System 2.0, Finder 4.1.

Download:

ZIP: System 2.0.dsk.zip

HQX: System 2.0.image.sea.hqx

System 3.3

System 3.3 (1987)

Macintosh System 3.3, contains Appleshare networking.

Download:

ZIP: System_3.3_512k_Appleshare.dsk.zip

HQX: System_3.3_512k_Appleshare.image.sea.hqx

Macintosh SE/30 restoration and networking

I recently picked up an SE/30 that was advertised in my local area.  It wasn't in the best of condition, the seller was honest about it needing several power cycles to start up properly.  But on the plus side it was capable of booting from the internal hard drive and what really caught my attention was that it had an Ethernet adapter installed.  From the back you could see both the AUI 15 pin and RJ45 jacks.  Ethernet cards for SE/30 are fairly rare so I thought this was a great opportunity to get hold of one.  I made an offer and managed to buy the machine for a reasonable price.



On getting the machine home, I inspected the case and overall it was reasonably good.  It had some patchy yellowing and it also had some engraving on the back, but there were no cracks or any other damage.  On powering the machine up it displayed the typical jail bars several times before eventually booting from the hard drive.  Once the machine booted I could see that the CRT had some screen burn in the picture.   This wasn't good at all as screen burn can't be fixed.  Luckily I have a spare CRT from a Mac Plus parts machine, so the plan was to swap the CRT with that one.  There were some stickers on the back which I removed and these left patches of white on the back.  So considering this I  thought that this machine would be a good candidate for retro-brite.



After a short test of the machine I could see that it generally worked when booted.  But on subsequent power cycles it would continuously display the jail bars until eventually booting to the desktop.  So considering this it was time to take it apart and start diagnosing what the issues were.  One possible cause of the jail bars on these Macs is the connection between the RAM and logic board or the ROM and logic board.  I removed all the RAM, it had eight 1meg SIMMS installed.  I also removed the ROM.  The logic board was in very good condition, there were no visible signs of capacitor or battery leaks.  Although on closer inspection I scraped around the caps with some cotton buds and I did manage to clean off some capacitor goo that wasn't easily visible.  I gave the logic board a good clean with a brush paying special attention to the RAM and ROM slots.  On re-assembly I still got the jail bars on start up.  I tried removing the logic board again and giving it a second clean up and eventually I managed to get rid of the jail bars on start up!



The machine now starts up normally every time.  So I suspect the issue was a short on the logic board either caused by dust in the RAM/ROM slots or by the capacitor goo that I cleaned off  but all things considered this was an easy fix.  The logic board will need a re-cap at some stage, as the capacitors are leaky and also the sound isn't working which is a typical symptom of bad caps.  But for the moment everything else seems to work fine.

Now that the machine seemed to be booting consistently I decided to take everything apart for a good clean up.  There was a nice surprise when I looked at the hard drive, it was a Quantum 500mb SCSI.  This would have been upgraded at some stage as these machines originally came out with either a 40meg or 80meg drive.  A 500mb 50 pin SCSI drive is a great score as these larger 50 pin SCSI drives are rare. 

The floppy drive was extremely clogged up with dust, one of the worst that I've seen.  I removed the eject/insert mechanism from the floppy drive and  gave it a good clean out.  I also lubricated the mechanism with some lithium grease.  Once cleaned out and serviced it seemed quite good.  I  gave all the internal components a good clean out and they all seemed good.  The Ethernet card in the machine was a DaynaPORT E/SI30, it seemed to be in good condition.



I removed all parts from the plastic cases and treated them with 40vol peroxide cream.  This worked great, all yellowing from the case was gone including the patches where the stickers were on the back.  This process works wonders.  The case is now a nice clean even white colour.  Once the peroxide process was finished I cleaned everything up and re-assembled the machine.  I replaced the CRT with the spare CRT from the the Plus.  On power up everything worked fine.



The next step with this machine was to see if I could get it on the network.  I re-formatted the hard drive using the System tools floppy and installed a clean copy of System 7.5 from floppy disks.  The floppy drive worked perfectly.  I also tracked down the driver for the DaynaPORT E/SI30 card and installed that.  Using the DaynaPORT hardware diagnostics I could see that the Ethernet card was recognised and reported to be  working.  I also installed Fetch FTP to connect to my local FTP server on my pc. 



On connecting a network cable from the RJ45 port on the DaynaPORT card to my local network hub I noticed that the activity light on the DaynaPORT started to flicker, this was a good sign.  However, there was no activity light on the hub.  I configured the MacTCP on the SE/30 with the appropriate settings.  I selected a manual IP address which was valid for my local network and I put in the correct gateway and DNS server IP's.  But on attempting to connect to my local FTP server using Fetch FTP there was no connection.  The fact that there was no activity light on the hub was an indication of a hardware problem.  I posted a question on 68kmla.org and I soon got a response indicating that the issue may be that the old DaynaPORT network card running at 10mbps and half-duplex, is not being detected by newer network hardware.  This in fact was the case.  Apparently many of these old network cards don't broadcast the speed and duplex that they run at, so they are not detected by newer network hubs and routers.  Even though newer network hardware will support equipment that runs at 10mbps, they require the equipment to broadcast the speed and duplex that they run at.

There are a couple of solutions to this problem, one is to get an old 10mbps hub and connect it in-between the old network card and the newer hub/switch.  The other solution and the one that I took, was to get a router that supports switching one of the ports to 10mbps.  It was suggested through the post on 68kmla.org that the Linksys WRT54G was one such router.  These routers are fairly old now and I was able to pick up two of them for $10 each.  Depending on the version that you get some may just automatically detect a 10mbps device but the ones I got didn't.  Luckily there was a fairly simple solution, I installed DD-WRT firmware on both routers and configured them to run as switches.  This involved turning off most of the features of the router like DHCP, routing and wireless.  See this great guide for setting up the Linksys WRT54G as a switch.  Once DD-WRT is installed you can configure each port through the VLAN settings.  To set the port for 10 megabit, un-check: autonegotiate, 100 Mbit, and full duplex for one or more ports.  Once this was done the connection to the DaynaPORT was detected and I was able to connect the SE/30 to the network.



One further enhancement that I want to do is configure the Linksys WRT54G as a wireless switch.  This would enable the SE/30 to become a  wireless client.


Compaq Portable III

Compaq Portable III

I recently acquired this Compaq Portable III from someone in my local area.  This is the third machine in the series that Compaq produced.  I also have the original Compaq Portable.  This one has a Intel  80286 processor, 640k of ram, a side mounted 1.2mb 5.25" floppy and a 20 megabyte hard drive.  It also has a monochrome LCD screen, which was a major improvement over the small CRT that the previous models had.  These machines were released in 1987.



 Compaq Portable III specifications
Manufacturer    Compaq
Release date 1987
CPU Intel 80286
Speed 12 MHz
Ram 640k (expandable with custom module)
Rom EEPROM
Storage 1.2mb 5.25" floppy, 20meg HD
Expansion Available with external module
Ports

1 x serial, 1 x parallel, 1 x RGB out

OS

Compaq/MS-DOS 3.1



When I checked this machine out it was the usual scenario with old computers, it powered up but wouldn't boot as the configuration had been lost.  It didn't come with any boot disks either so I couldn't really do any testing on it aside from seeing some text come up on the screen.  I thought this was good enough.  I felt pretty confident that I could boot it with some MS-DOS 5.25" disks that I already have.  On getting the machine home I tried getting it to boot from a floppy but unfortunately I couldn't  get it to boot (more on this later!).

I tried several 5.25" MS-DOS boot disk that I have but none of them would work.  The drive light would come on as expected to scan the disk but the screen would just repeat the "missing system disk" message.  This was disappointing as I started to think the floppy drive was faulty.  I proceeded to take the back cover off, there's six Torx screws holding the back cover on, once removed it comes off quite easily.  Removing the back cover exposes the motherboard and allows removal of the drive cover which exposes the drives.  I could see there was a hard disk installed as well as the floppy.  With the removal of one more Torx screw the drive assembly can be pulled out of the machine from the side.  I tried plugging in a 3.5" floppy drive and booting from that but that didn't work either.


Floppy drive gotcha!
After doing some online troubleshooting I discovered that to engage the floppy disk head you need to put the disk in until it clicks then press the eject button in.  This engages the head onto the disk.  This was quite a discovery because I realised that I wasn't engaging the disk properly on previous boot attempts.  Once I followed the correct procedure for inserting the disk, the machine booted as expected.  I was also able to examine the C drive which proved that the hard disk was working fine.

Compaq III setup
In my reading about this machine I also discovered that unlike other pc's it doesn't have a BIOS setup in ROM.  The only way to configure the BIOS is via the Compaq setup utility which comes on disk.  You can find the setup disks online but unfortunately they come as an extremely annoying exe file package.  There are two versions of this package, one to create 360k 5.25" boot disks (sp0316.zip), and one to create 720k 3.5" boot disks (sp0308.zip).  But are your ready for this, the 360k exe file is 550k in size, so you can't just copy it to a 360k disk.

I managed to use DOSBox on a modern pc to run the main exe, this looked promising as I'd hoped it would extract the utilities which I could then simply copy to a disk.  But no, running the initial exe just extracts some files which then must be run to create the physical disks.  I tried doing this on my IBM 5150 but it wouldn't work.  The Compaq utility wouldn't recognise the floppy drives on the 5150, very annoying.

After some searching online I was lucky enough to find a site where the setup utility files had been extracted from the irritating Compaq archive and made into a 720k disk image.  I was able to use WinImage to easily extract the files and put them on a 5.25" disk.  Once I did this I was able to run the setup utility on the Compaq III and configure the hard drive and other BIOS settings.  For anyone else who needs these utilities here they are in a simple zip.

These are the files contained in the 720k version of the setup disk.  The utilities can be separated if you need them on a smaller disk:

compaq_portable_iii_setup.zip (384.43 kb)

- INSPECT.EXE
- MDMI.EXE
- README.CPQ
- README.TXT
- SETUP.EXE
- TEST.COM
- ARSTART.COM
- DIAG.CPQ
- DIAG.EXE
- DIAG.OVL

The physical condition of this machine is great, after a good clean up it's come up in mint condition.  The only exception being the curly keyboard cable.  These are notorious for decay and mine is no exception, the shielding on the curly cord is crumbling, so that will need to be fixed at some stage.  But aside from that this machine works perfectly, I can boot from the hard drive and run applications, the keyboard works well too.



21 Feb 2016 - Compaq Portable III leather carry bag

When I picked up the Compaq portable III a few weeks ago it came with a carry bag.  The bag was quite dirty and ratty looking but today I decided to see if it would clean up.  On closer inspection the bag is a genuine leather Compaq carry bag.  I gave it a good clean with leather cleaner and conditioner.  I also polished up a few scuff with leather shoe polish.  The bag came up looking really good.

Altair 8800 with FDC+ and 5.25" TEAC 55GFR dual drives

A project that I've wanted to do for a while is to set up the Altair with dual disk drives using the FDC+.  A few weeks back I managed to get hold of another TEAC 55 GFR drive thanks to a contact on the VCF.  So I finally got around to configuring both drives to work with the FDC+.  The new drive is a TEAC 55 GFR 612-U, it's a slightly different model to the other drive that I use which is a TEAC 55 GFR 149-U.  The 612-U has different jumpers to the 149-U but I managed to configure it close enough and it works fine with the Altair.

To hold the disk drives together I'm using a 5.25" drive rack that I cut out of an old pc.  I'm also using an AT power supply from the same pc to power the drives. 



Two TEAC 55 GFR floppy drives



Jumpers set on the TEAC GFR 612-U, drive set to D0 (disk 0)



Jumper settings on the TEAC GFR 149-U, drive set to D1 (disk 1)



The dual drive unit assembled and connected to the Altair



The Atlair running 63k CP/M with directory listings from both drives A and B


Running Ladder game under CP/M

Macintosh Mystic Colour Classic

A few weeks back I saw a Macintosh Classic advertised for sale on a local site, it wasn't really a model that I wanted but it had a nice M0487 ADB keyboard and mouse which I did want and the price was good so I decided to go an have a look.  While I was speaking to the seller I asked him if he had any other Mac stuff that he want to sell and he brought out a Macintosh Colour Classic with keyboard.  The Colour Classic didn't work but it was in great condition so I made an offer on both machines and got them for a very good price.


       


On getting the machines home I tried to power up the Colour Classic but there was no activity, I tried all the recommended easy fixes like replacing the clock battery and ensuring the keyboard was properly plugged in.  This model won't boot unless a keyboard is attached because the start button is on the keyboard.  But nothing worked.  On pulling out the logic board it struck me that it was very similar to an LC575 board that I'd picked up the week before.  I got a non-functional LC575 the previous week for $20, I needed a SCSI hard drive and floppy drive for my SE/30 restoration (see posts in archive regarding the SE/30 and LC575 dis-assembly).  So I put the LC575 board into the Colour Classic and it powered up!  It wouldn't load the OS but it went to the start up screen and was clearly functioning.  Quite a lucky coincidence that this board fit this machine and also considering both the Colour Classic and LC575 were non-functional but for different reasons.  The LC575 most likely had a bad power board and the Color Classic had a bad logic board.


           


On doing some research on the Colour Classic I discovered that upgrading a Colour Classic with an LC575 board is called the "Colour Classic Mystic upgrade".  You've got to like that.  Thanks to some detailed information on the web about the Mystic upgrade, I was able to patch a version of system 7.5 to install on the upgraded machine.  The issue with the OS is related to the screen resolution, the LC575 has a 640x480 resolution whereas the Colour Classic has 512x384.  So you need to patch a version of Mac OS so it thinks it's installing the system on an LC575 with 512x384 resolution.  There is a great website which goes into detail about the Mystic Colour Classic upgrade and they have a guide on how to patch the system for use on the Mystic upgraded machine:  

http://colourclassicfaq.com/mobo/mystic.shtml

The zip file below contains System 7.5 patched for the Mystic Colour Classic:


Mac Mystic Colour Classic System 7.5

System 7.5 for Mystic Colour Classic

Download:

ZIP: System_7.5_Mystic_patched.zip (9.56 mb)


Before doing the install I needed to fix the floppy drive. The floppy was in a similar state to the one I extracted from my Macintosh SE/30, see my post about the Sony SuperDrive head spring fix.

The logic board from the LC575 is a drop in replacement for the Colour Classic but the rear connectors don't line up with the back plate from the Colour Classic.  So I adapted the back plate from the LC575 to fit the Colour Classic.  It fits well but I had to drill new holes to hold it on.  I also bleached it with 40vol cream peroxide to get a better colour match.  I was really pleased with the result.  The left picture below shows the original Colour Classic back plate at the top and the LC575 back plate underneath (cut into two pieces).  The second picture shows the LC575 back plate cut down to fit the Colour Classic.  The third and fourth pictures show the finished back plate.


         



The 4.5v clock battery on the LC575 motherboard was long dead as you'd expect so I replaced it with an "AA" battery holder which takes three batteries.  Each "AA" battery is 1.5v so this makes up the 4.5v required.  It also allows for easy replacement of the batteries unlike the original unit. To finish off this machine I added a PDS ethernet card to allow for easy transfer of software via FTP.  The image below shows the LC575 logic board with "AA" battery holder and PDS ethernet card.




Commodore 64C repair

A couple of months back I picked up this C64C for $10.  I suspected it wouldn't work but the case and keyboard were in very good condition, so if nothing else I though it would make a good parts machine.  On powering it up I got a very snowy picture, no colour and no basic prompt, but the typical C64 border could be seen, so there was an indication that something was working.


    


I took it apart and tried re-seating all the removable chips, there wasn't many as most were soldered.  Re-seating chips made no difference.  I eventually tried inserting a cartridge and that worked, although the snowy video was still there.  So at first I figured the problem must be the ram.  I bought some replacement ram chips and tried the piggy back trick but it made no difference.  I've got a C64 breadbin that I use for parts and most of the major chips in that machine are socketed so they can be easily removed.  I piggy-backed U3 (Basic ROM - 901226), from the spare machine and I got the Basic screen and prompt.  I entered some Basic commands and loaded a game using the SD2IEC and everything worked fine.  I de-soldered the bad 901226 and replaced it with a 24 pin socket and put in the replacement Basic ROM.


             

There was still the problem of the snowy video.  After doing some reading online I simply adjusted the pot near the VIC chip and this fixed the snowy video and colour.  See green pot in the top right of the square in the pic below.


           


There's still one problem with this machine, the audio output is very low.  I only get very faint sound through the TV.  I've checked the SID chip it's not that, so I suspect it may need some capacitors replaced.  Another C64 resurrected from the dead.