21 Mar
2010
21 Mar
'10
9:46 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell
Verzonden: zondag 21 maart 2010 20:08
Aan: cctalk at classiccmp.org
Onderwerp: Re: HP 2671 Graphics ROM
Yes U13 is empty, U14 are empty holes.
No RAM at all on the board, the dipswitch 2K is open too.
So I suppose I can place a 6116 in the U13 socket, and switch the 2K
dipswitch to closed, to have the advantage of a smal hp-ib buffer.
Should speed up data transfer a little..
PSU is indeed the same, HP-IB board is the same
02670-60072
Rev.A ROM
(U15) 02670-80078, Processor (U2)8039, (U13)
Empty socket.
DO you mean U13 is empty? What about U14? Is there a 2K*8 RAM (2016,
6116) on this board at all? Printerboard
02670-60084 ROM (U101) 1818-1819, Processor
(U301) 8049
1820-2731.
Dipswitches are the same, for as far I can see the
difference is U301,
the
I assume the DIP swithc on the HPIB board is set differently
because your board uses an external ROM and mine doesn't.
service manual speeks of replacing one chip.
Right. Sounds like I'd better have a go at buildign a device
to read out 8049s... The interface boards seems to be field
replaceble, in my
opinion it make no
sense to put the graphic rendering on the
interface board.
I think it was actually user-changeaable (you could swap the
interface board if your needs changed), rather like the HP7225
plotter.
You just
undo 2 screws on the back and slide the board out -- without
even taking
the case cover off.
-tony
-Rik