manual / info on Commodore PC50-III aka 386SX-xx

[silverdr]

... is higly welcome here. Especially I am interested in the DIP switch
settings' meanings, jumpers descriptions etc.

[Ronald van Dijk]

Hi,

Post by silverdr
... is higly welcome here. Especially I am interested in the DIP switch
settings' meanings, jumpers descriptions etc.

The PC50-III is was used in Commodore's Slimline Series PCs. These systems
can have either a 286 or a 386SX CPU on a separate processor card. The
PC50-III mainboard was of designed/built by Commodore, but there also exist
Commodore Slimline Series PCs with a 286 or 386SX CPU which were based on
a mainboard by DTK.

Anyway, the jumpersettings for the PC50-III mainboard are:

JP101 In: 386SX Out: 286
JP102 In: 8 Bit BIOS (*) Out: 16 Bit BIOS
JP103 In: IOL=24ma (*) Out: IOL=12ma
JP104 In: 386DX Out: 386SX (*)
JP701 In: RTC=170H (*) Out: RTC=70H
JP702 (1) In: fwp=187ns Out: fwp=125ns (*)
JP703 (2) In: ftssm enabled Out: ftssm disabled (*)
JP704 In: enable disk chg Out: diskable disk chg (*)

(*) = default switch position
(1) = floppy write precompensation (see WD37C65 spec)
(2) = floppy two speed spindle motor

There is also a DIP-switch, SW501, which controls settings regarding the VGA
controller. I could not find further information on this DIP-switch.

Regards,
Ronald

[silverdr]

Post by Ronald van Dijk
Hi,

Post by silverdr
... is higly welcome here. Especially I am interested in the DIP switch
settings' meanings, jumpers descriptions etc.

The PC50-III is was used in Commodore's Slimline Series PCs. These systems
can have either a 286 or a 386SX CPU on a separate processor card. The
PC50-III mainboard was of designed/built by Commodore, but there also exist
Commodore Slimline Series PCs with a 286 or 386SX CPU which were based on
a mainboard by DTK.
JP101 In: 386SX Out: 286
JP102 In: 8 Bit BIOS (*) Out: 16 Bit BIOS
JP103 In: IOL=24ma (*) Out: IOL=12ma
JP104 In: 386DX Out: 386SX (*)
JP701 In: RTC=170H (*) Out: RTC=70H
JP702 (1) In: fwp=187ns Out: fwp=125ns (*)
JP703 (2) In: ftssm enabled Out: ftssm disabled (*)
JP704 In: enable disk chg Out: diskable disk chg (*)
(*) = default switch position
(1) = floppy write precompensation (see WD37C65 spec)
(2) = floppy two speed spindle motor
There is also a DIP-switch, SW501, which controls settings regarding the VGA
controller. I could not find further information on this DIP-switch.

Thank you very much. With this I managed to revive the machine. The DIP
switch has only four bits so I went through all the 16 combinations and
found that the most usable one is up-dn-up-up. It gives a kind of colour
VGA output.

Heh, I am not sure if it is fast enough but maybe I can run some famous,
CBM related DOS based applications on it :-)