It should be easy enough to install on a test system, check the address space where typical bootstraps go, see what's there, etc. Thanks.
On Wed, Oct 7, 2015 at 4:58 PM, Brent Hilpert <[email protected]> wrote: > On 2015-Oct-06, at 9:18 AM, Henk Gooijen wrote: > > -----Oorspronkelijk bericht----- From: william degnan > > Sent: Tuesday, October 06, 2015 2:26 PM > > To: cctech > > Subject: DEC pdp 11 "R-K ABBR. BOOT P. C. Board" > > > > What is the purpose of this controller? It came with a PDP 11/05 system: > > > http://vintagecomputer.net/digital/PDP11-05/dec_r-k_abbr_bootPC_Board-a_front.jpg > > > > Printed on the controller is > > R-K ABBR. BOOT P. C. Board 609395 Rev B > > 802000 Rev > > > > I searched around, found nothing specific Is this a bootstrap board for > an > > RK drive? > > -- > > Bill > > vintagecomputer.net > > > > ========= > > I am clueless too, but if you want to play Sherlock Holmes, > > it should be possible to figure it out. > > 20 ICs, several will be familiar in use in circuitr for the bus. > > I'd first check whether it is intended for UNIBUS (likely) or QBUS. > > Given the IC types you can estimate the circuit complexity. > > If there are lots of simple gates it is just a puzzle. > > The board has good quality machined pins, so after making pictures > > and a drawing the location of each IC, you could pull them and > > trace every pin, visually and with an Ohm meter. Lots of work, not > > difficult, but very time consuming ... > > Good for the dark evenings :-) > > > IC date codes are 75/6, I guess that's just late enough to be QBUS, but > more likely UNIBUS. > > Can't discern all the IC types but some speculation based on what can be > seen: the labeled IC could be a 256*4 PROM, when a memory read-cycle is > initiated the 74221 monostables sequence the reading of 4-bit chunks into > the the 74175 latches to make up a 16-bit word for presentation on the bus. > The jumpers at centre-bottom could be the base address. > A 256*4 PROM would give a 64-word bootstrap. > > Easy board to reverse-engineer. > > -- Bill vintagecomputer.net
