Retro Computing

This story starts back in 1986 when I decided to purchase the original Amiga computer, the A1000.  This computer in my mind blew everything else away at the time. IBM compatible PCs were big boxy devices with limited colors, poor sound and well you know the OS. The Macintosh was a machine with that really small monochrome screen. The A1000 on the other hand could display up to 4096 colors, had stereo sound with 4 channels and featured a preemptive multitasking operating system.

Besides playing games the thing that I liked to do with the Amiga was ray tracing and animation. I was fascinated by all of the sample images and animations that were coming out at the time.  I would spend hours working up the models and then waiting for the images to be rendered with Sculpt-Animate 4D. The bad thing was the render time which was painfully slow on a 68000 processor running at a mere 7.16 MHz. That spurred my need to turbo charge my A1000 to reduce all of the wait time.

Fast forward a couple of years and a magazine article hits the stands that features a 68020 daughter board that could be purchased for the user to populate (the LUCAS board). In addition to the 68020 processor, the daughter board would have a socket for a 68881 floating point co-processor. That was exactly what I needed to speed up my ray tracing. I quickly purchased one of the boards and hand soldered all of the sockets and populated the components. Now I had a 68020/68881 combo that could run in the 16-20 MHz range. That was a big boost but there was more to come when the next article in the series came out which featured a memory expansion card for this board (the FRANCES board). I grabbed one of those and assembled it and now I had some 32-bit memory running with the 68020 at higher speeds than the 16-bit A1000 motherboard RAM. The turbo charged A1000 system served me well for a few years but it was always floppy based and I eventually grew tired of the load times.

The next step up occurred in 1992 as I recall. The A1200 was introduced which had a native 68020 processor running at 14.32 MHz, 2 MB of RAM and an IDE interface for a hard drive. As far as processing speed this was a step down from my turbocharged A1000 but a step up with the hard drive interface and improved graphics and more native RAM. So the next logical step was to turbo charge this new machine. That led me to a GVP Turbo+ Series II that featured a 68030 running at 50 MHz along with a 68882 floating point co-processor. Talk about a big boost for my rendering times compared to the earlier A1000 with only a 68020/68881 running down at 20 MHz.

I ran these Amiga systems for many years although I always had to have one of those PC boxes for work. PCs were just boring machines to me that were required in order to run various applications. The Amiga systems were fun and exciting since in the early days there was no other desktop computer that could really compete with them.

August 2022

My Amiga systems have been in storage for a few years now and I was curious to see if I could get one booted up again. The A1200 was easy to get to so I pulled it out and cleaned it up. I also grabbed the 1986 vintage 1080 monitor that I had bought new with the A1000 all those years ago. The monitor came up and seemed fine but the A1200 was not booting. I decided to pull the turbo board out of it and then it booted right up with the native 68020 processor!  Now it was time for a few rounds of Lemmings which was one of my pastimes when the A1200 was much newer. One issue I'm having is the left mouse button which has a barely functioning switch from all of the prior clicking. I ordered some new tactile switches and will get those replaced to try and rehabilitate this original mouse.

Next up will be some experimenting with the GVP turbo card to see if I can get that functioning again. It doesn't have that many components so there isn't too much that could go wrong with it (we'll see though).

I also want to get out the old A1000 and see if that will boot up. I fear that it will have capacitor issues and possible some corrosion issues.

The 1992 vintage Amiga 1200 is still in relatively good shape with the exception of the mouse buttons and the yellowing keys on the keyboard. I'll get the mouse buttons replaced and see if it will work like new again.

The 1986 vintage 1080 monitor from my A1000 system is still going strong and up to the task of a few games of Lemmings. I'm a little rusty on Lemmings since I blew the hole in the top level so that all of those Lemmings are trapped over a fire pit! I wish that these original monitors had stereo speakers instead of combining the stereo channels into one speaker.

After a bit of experimenting I was able to get the A1230 Turbo+ to boot as seen above by the 2 MB of chip RAM and 4 MB of memory on the turbo board. I was able to do this by removing the DS 1494 real time clock/battery. These are only rated for 10 years and it is long past its prime. I don't think that these clocks in a can are available anymore so I will have to figure out a different RTC.

August 29, 2022

The mouse on the A1200 was repaired by ordering a tactile switch assortment that included the size of 6x6x4.3. I went ahead and replaced both of the switches which requires desoldering 4 pins on each. Note that there is a screw on the mouse hidden under the label on the bottom. The label on mine was metallic so it was easy to remove in one piece with an Xacto knife. The mouse works much better now although I think that these switches are stiffer than the original and produce  loud clicks!

September 12, 2022

Today I broke out my 1986 A1000 to try and get it up and running again.
Amiga 1000 Testing