Amiga 1200 upgrade

Today as a little change to recent posts mainly focused on DAP and software development I would like to show computer, which I’ve theorethically finished renewing some time ago, but for different reasons I didn’t wrote about – Amiga 1200.

Amiga 1200

I’ve got it in mid 2018 and I’ve worked on it gradually in 2020-21 period. It was in pretty good shape, was recapped by previous owner, which was sort of relief, because I didn’t have equipment for soldering SMD components. It had also internal, mechanical hdd, which was dead on arrival and 6MiB Fast Ram extension with place for FPU. Newer, lighter power supply reeked like dead fish, normal thing after capacitors leak, but it turned out to be ok. Still have to open it some day and remove this bad smell. I didn’t have to interfere with internal cabling, which was great. It’s second unit I’ve owned. First one I’ve had to sell many years ago to pay some bills, which I regretted much later, oh well… But here it is once again …

I didn’t want to go over the top with it, just wanted to have classic AmigaOS machine for games, demos, software development.

First thing I did was cleaning up the case and keyboard, exchanging physical hdd to Compact Flash adapter with 4GiB CF card, then opening up floppy disc drive to clean it with isopropyl alcohol. After that I could install operating system and all other basic stuff for file transfer – I mainly used pcmcia CF card adapter with PC formatted CF card.

A1200 internals with AC1233n / Indivision mk3 and RTC (not visible)

To speed up A1200 I’ve got ACA1233n-40 (mc68030 with full MMU, 128MiB of Fast Ram) and real time clock module from IComp GmbH. To prepare motherboard or rather revert Commodore / ESCOM production mistakes for ACA1233n I had to desolder several SMD components as stated in installation manual.

To have possibility to connect easily to modern displays I’ve bought Indivision AGA mk3 and this was the main reason I was holding post about this upgrade. I just couldn’t manage to mount hdmi connector on rear panel. To do it I had to get proper cube mount and attach it to removable panel under the floppy. I’ve used Ettinger cube standoff, threaded M2.5/M3 05.60.223. It turned out that is hard to find in reasonable price, in reasonable amount (not 100 pcs. at minimum), in reasonable time (not several months of waiting). After I got them I only had to drill two holes on the rear removable panel, make a hole for hdmi port and attach it with four screws and some pads.

Fitting Indivision was little laborous, because some parts of metal shielding had to be cut with Dremel tool and this basically means that whole unit had to be completely dismantled. And cutting metal is messy and isn’t very pleasant.

Indivision HDMI port mount, screws could be the same on both sides, but these are only ones that I’ve found.

Latest addition was update of AmigaOS 3.2 and kickstart ROMs replacement everything was done. Today just installed upgrade to 3.2.1 and used ACA maprom feature to not have to buy or program new kickstart EPROMS.

Workbench AmigaOS 3.2 via Indivision on LG 32UD99-W

For now everything works fine and I’m quite happy with it. Maybe in the future I will replace internal floppy with something better working (ALPS replacement didn’t deliver), add internal/external boot drive switcher, change internal hard drive to something bigger than 4GiB, change keycaps to US along with mylar and change case to new one if I find it for reasonable price. Probably soon I will post something about Amiga 500, which also waits to be properly documented.

O wpisie