Found these inside a non-working 71B

[Dave Frederickson]

(03-14-2018 03:56 AM)rprosperi Wrote:  

(03-14-2018 03:39 AM)MikeSD Wrote:  Regarding FREE:PORT (0.04) That doesn't work but .05 and .06 do.

Interesting. Perhaps the IL Mailbox (usually hidden port 0.04) must stay at that port address, and the added RAM picks up at the next available port (0.05 & 0.06).

Can you try SHOW PORT (after FREE-porting both 32K banks)? This should confirm the HP-IL ROM is 16KB, type=2, PORT(0.07) which should clarify all remaining unknowns.

The MATH ROM is at Port(.04). Second, unless DOUT from the last 32k module was connected back into the daisy chain, the HP-IL Module, if installed, will go undetected.