RE: 8250lp parts

Hello William,

> I have constructed a 8250lp parts list, mainly from the schematic.
> The schematic shows ROMs, but all the part numbers are for EPROMs.
> Were there any actual ROMs? If so, were the same ones as the 8250?

At the 8250lp (and the 8296d) there used an new pcb. This pcb exists in
three (!) revision. And one (or only?) differences about this revisions are
the roms. So there exists an revision with 24 pin sockets for 2364 roms with
active chip select. So you can use the same roms with dos 2.7 as the normal
8(0/2)50.

There exsits an other revision with 28 pin sockets. So you can use 2564 (not
2764!) eproms. The content seems to be equal. But i don't have checked it. I
don't own a pcb with 28 pin sockets! This must be the parts 251165-01 (same
as 901887-01) and 251166-01 (same as 901888-01).

So for the gcr decoder (901467-01 or only 901467) exists an eprom version
(2516), too. This is the part 251167-01 with the same content as 901467-01.

Any other strange fact exists. I found a part number 251256-02 for a
6530-050 rriot. But this chip doesn't see anybody. All known 8250lp (and
8296d) use the adapter board with an eprom for the dc code.

dos:
> UA13          901887-01    2364 ROM DOS 2.7 C000-DFFF
> UA11          901888-01    2364 ROM DOS 2.7 E000-DFFF
or
> UA13          251165-01    2564 EPROM DOS 2.7 C000-DFFF
> UA11          251166-01    2564 EPROM DOS 2.7 E000-DFFF

disc controller:
> UAB3          251256-02    6530 RIOT DOS 2.7
or
> UAB3                       adapter card

gcr decoder:
> UC1           901467-01    2316 ROM GCR
or
> UC1           251167-01    2516 EPROM GCR

In one or two weeks, i will search for the photos from the different
revisions!

Martin


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