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View Full Version : Bullet Wave Mate 286 motherboard memory



huubwen
July 15th, 2012, 04:55 AM
I disassembled an old Bullet Wave Mate 286 system today.

It is quite an unusual system. Although it has an AMD 286-6 CPU it only has 8-bit ISA slots. Configuration is done with the usual XT dip switch block. Real time clock is provided by an external ISA card.
The CPU is labeled C80286-8/C2. AMD changed in 1985 the naming convention for CLCC processors from C80286-<frequency> to R80286-<frequency>. So I think the board and CPU are prior to 1985.

The motherboard has 512 KB memory. I would like to swap or expand the memory to 640 KB. The existing memory is counted and verified correctly by the BIOS. MS DOS gives a boot error “RAM Parity Error Detected”. Nevertheless it allows me to continue and the system seems running fine.

I cannot find any information about the board on the internet.

The XT DIP switch support 4 banks of memory. I cannot identify the memory chips and what chips belong to what memory banks. Can someone help?

Second a capacitor between slot 8 and 7 is disconnected at one side. The soldering at the disconnected end looks perfectly flat and not touched or broken. It looks like it has been all the time like this. What could be the reason for this?

9683

Stone
July 15th, 2012, 05:18 AM
It looks like the board has two memory banks with 256K in each bank. It doesn't appear that you can put any more memory on the board so to do so you would likely need an expansion memory card to get to 640K. As for the parity error... there is probably a bad chip in the array, most likely the last chip in one of the banks as that would be the parity chip.

modem7
July 16th, 2012, 12:31 AM
I cannot find any information about the board on the internet.
A magazine advert for the Wave Mate Bullet 286 is now at http://www.minuszerodegrees.net/images3/wave_mate_bullet_286.jpg

SpidersWeb
July 16th, 2012, 11:04 AM
I have the a slightly newer version, the 286E, it'd only ever see 512K despite having much more on-board - the rest was used for ROM shadowing and disk caching (quite annoying) but I'm hoping yours just goes to 640K when a 128K expansion is installed.

They're XT's with 286 CPUs so you can use things like the Lansoft ROMs - although I'm assuming your model is just as XT as my 286E (1987ish).

Stone has covered it off though, probably a bad parity chip. Mine has a bad memory problem as well, but it appears to be a board fault - I used the Lansoft XT ROMs and known good memory chips to find out why it wouldnt' start any more. I had found quite a few dry joints etc, but the repairs didn't fix the boot issue, so I eventually put it in the 'do it later' pile.