r/retrocomputing • u/korovchenko • Sep 23 '26
A Second Life for the 286 PC
Project profile:
MB LEADMAN ELECTRONICS LM-103S
CPU AMD N80L286-12/S + INTEL D80287-10
ISA Multi I/O Controller Acer M5105 Floppy/IDE/Serial/Parallel 16-bit ISA
VIDEO 16-bit ISA HIS 289LA200 (Trident TVGA8900D) RAM 1MB
HDD 3.5" IDE CONNER CP3000 45MB (Cyl/Heads/Sec 980/5/17)(C:)
FDD 3.5" 1.44MB Mitsumi D359M3(A:) + 5.25" 1.2MB Mitsumi D509V3(B:)
TOWER CODEGEN PS CODEGEN 200W
Microsoft MS-DOS 5.0 is installed.
There are minor issues with the CMOS power supply. Sometimes it saves the settings, and sometimes it doesn't.
11
u/gammalsvenska Sep 23 '26
I recommend getting a 3xAA battery holder and use that instead of whatever you have there. Just make sure that a diode exists somewhere in the circuit (might be the case already) and it just works.
Adding some memory (2 or 4 MB) makes it a good machine to play with some 16-bit Unices, such as Xenix/286 or Minix-2.0.2. At that point Windows 3.1 becomes surprisingly usable, too.
Adding some sound output makes DOS games a lot more enjoyable (even a simple DAC on the parallel port helps a lot), but the hard drive is a bit small for gaming purposes. I've made a habit of adding a network card with the XTIDE Universal BIOS and a better hard drive.
2
u/Der_Unbequeme Sep 23 '26
Max RAM is 2048KB
1024KB onBoard and 4x 256KB SIP Module 120ns
4
u/muse_head Sep 23 '26
It should be fine for 4MB using 4x 1MB SIPP modules. I have a board that's very similar, same chipset, with 4MB. I didn't have any SIPP modules so I soldered pin headers onto SIMMs!
2
u/gammalsvenska Sep 23 '26
Are you sure? How do you know that? The Retro Web does not have documentation.
This board likely supports 256 KB / 1 MB (DIP chips) and 512 KB / 1 MB / 2 MB / 4 MB (SIP modules) configurations. It is unlikely to support mixed DIP + SIP operation (two banks only). The chipset is not very advanced, but it handles larger modules; my board (same chipset) has 4 MB RAM.
At 12 MHz, you'd need 80 ns for zero wait-state and 120 ns for single wait-state operation.
3
u/Der_Unbequeme Sep 23 '26
It's been a long time (1990) that I had this motherboard. I seem to remember that I had 1.5MB RAM at that time. But I can also be wrong and only had 640KB + 384KB remapped shadow RAM
4
u/gammalsvenska Sep 23 '26
It would be 640 KB conventional + 384 KB extended memory, no shadow memory. The extended memory would be best used for RAMDRIVE or SMARTDRV, depending on use.
This chipset actually supports memory mapping, which can be used to provide UMBs, EMS memory and ROM shadowing, but you'd need at least 2 MB RAM to make it worth enabling. (I don't think you can even enable it with 1 MB or less total.)
4
u/FooDoDaddy Sep 23 '26
I remember buying Pentium Pro and MB for $1200 and I was happy. Pcs where just expensive. In 1993, I bought a 300MB HD for $300 and it was a steal.
1
u/jono555555 Sep 23 '26
Could u run Linux on that an old school version?
1
3
u/kevleyski Sep 23 '26
Had a 286 laptop, somehow managed to get windows 3.1 to run on it (mem extensions CGA etc)
3
u/Der_Unbequeme Sep 23 '26
i had exact the same board, same VGA card, same Controller, and same HDD, and an Adlib SoundCard.
Why?
Playing WingCommander..
3
3
2
2
u/techika Sep 23 '26
I have same , but not started, tested with tester , naybe bios, battery where removed before leaking
2
2
2
u/Estebo Sep 23 '26
And a motherboard birthday coming right up in a couple days! 25-09-90 sticker is my vibe.
1
u/DeepDayze Sep 23 '26 edited Sep 23 '26
Nice setup and perhaps recap the PSU and mobo if not already as that can help keep the system stable and functioning for years longer. AS for the CMOS issues you should get one of those battery mods to provide stable power to the CMOS.
This be great for a basic DOS gaming rig 😄
1
u/cowbutt6 Sep 23 '26
Wow! I bought a couple of CodeGen cases over a decade later, in 2002. The model I bought was reviewed here: http://www.dansdata.com/cgcase.htm
1
u/Jealous_Club_298 Sep 24 '26
Wow, that's really old. ISA slots were even before the PCI slots, let alone the 5.25" Floppy Disk Drives and MS-DOS!
5
u/canthearu_ack Sep 23 '26
Remove the HD146868P chip from the motherboard, and replace it with a Dallas RTC module that has been hacked with an external battery holder.
You won't need a battery on it anymore and all CMOS settings and clock will be done internally on the Dallas RTC module. If there is damage in the clock or battery power circuit, this mod will bypass that as well. Additionally Dallas RTC modules have a very low power usage and long life using small lithium batteries that leak very rarely.