Acorn BBC Micro minimal configuration:-
This is to try to get the machine working to a "Language?" prompt.
Disconnect the keyboard.
Then remove all of the following (if fitted and if socketed):
IC3 - System 6522 VIA
IC69 - User 6522 VIA
IC78 - 8271 chip or 1770/2 disk interface module
IC52 - ROM/EPROM
IC88- ROM/EPROM
IC100- ROM/EPROM
IC101- ROM/EPROM
IC89 -68B64 Econet
IC7 - Serial ULA 2C199
IC4 - 6850 serial
IC74 - uPD7002 analogue to digital converter
IC98 - TMS6100 speech system chip
IC99 - TMS5220 speech system chip
Leave in IC51 (OS ROM)
LINKS (jumper shunts)
S9 -assuming IC78 is not fitted/removed, fit a link/jumper shunt or resolder the bridging wire to S9.
S21 - fit two links as follows (if not already fitted): nw to ne AND sw to se (two each East-West).
S25 - note it’s position, then try the machine with it fitted in the south position. If the machine still fails to start, try removing link S25.
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Note that in this configuration, the OS is not in control of the sound system, so the speaker will make the continuous tone, so you may want to unplug the speaker.
Mark
Sorry if this has already been spotted, but
"IC74 - uPD7002 analogue to digital converter"
shouldn't it be
"IC73 - uPD7002 analogue to digital converter"
Texy
Statistics: Posted by texyuk — Sun Jul 28, 2024 11:18 am