test-drb May 2001

test-drb@ccmp.vtda.org

273 participants
642 discussions

by pete＠dunnington.u-net.com

On May 18, 17:14, Eric Dittman wrote: > > On May 18, Pete Turnbull wrote: > > > The standard (as far as I know -- the ones I have came from a > > > microPDP-11/53 in a BA23 case) boot ROMs are 23-261E5 and 23-263E5. I seem > > > to have accidentally left binary images in my DECROMs directory at > > > www.dunnington.u-net.com/public/ :-) > > > > Eric, do you have the facilities to burn these EPROMs? If not, > > I can help you. Feel free to contact me. > > Yes, I can burn most types of EPROMs, including > the ones on this board. Are they ordinary 27128s or something different? I've seen a lot of DEC EPROMs which had fewer pins than "standard" -- though AFAIR only 8KB ones. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

PDP-11/53

by mcguire＠neurotica.com

On May 18, Eric Dittman wrote: > > Eric, do you have the facilities to burn these EPROMs? If not, > > I can help you. Feel free to contact me. > > Yes, I can burn most types of EPROMs, including > the ones on this board. Good deal. -Dave

23 years, 7 months

PDP-11/53

by pete＠dunnington.u-net.com

On May 18, 13:41, healyzh(a)aracnet.com wrote: > On May 18, 14:06, Eric Dittman wrote: > > I've been gifted with a PDP-11/53 (or 53+) CPU module. > I just heard from someone a few minutes ago, that if you've got a 3rd party > disk controller that you can boot the system off you should be able to > simply remove the ROM's. Well, only if they fit, physically and electrically. Most 3rd-party boot ROMs I've seen (eg Dilog, Emulex, Plessey, GR, etc) wouldn't be the right type for the board. The code might work; I suspect the ROMs from an 11/73 or 11/83 might work. I never used an 11/53 much, but from what I remember it's pretty much like other 11/73+ or 11/83 boards, just with memory on it as well as SLUs and bootstrap etc. I've no doubt someone else (Megan? Allison? others?) can expand on the differences. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

Slicing open the top of a 48T02 Sun Sparc chip to replace bat tery is that thing hollow or filled with epoxy?

by Lee.Davison＠merlincommunications.com

> Has anybody tried one of the DALLAS "smart socket" products with this thingie? Unfortunately the 48T02 is a TOD clock and calendar as well as NVRAM, so there's no suitable SmartSocket to replace it. The registers have to be at particular places and use a particular protocol too. Just got the data sheet and the Dallas DS1642 is a direct form, fit and function replacement for the MK48T02(B). It says so right at the start of the sheet. Cheers, Lee. ---------------------------------------------------------------------------- ---- This email is intended only for the above named addressee(s). The information contained in this email may contain information which is confidential. The views expressed in this email are personal to the sender and do not in any way reflect the views of the company. If you have received this email and you are not a named addressee please delete it from your system and contact Merlin Communications International IT Department on +44 20 7344 5888. _____________________________________________________________________ This message has been checked for all known viruses by Star Internet delivered through the MessageLabs Virus Scanning Service. For further information visit http://www.star.net.uk/stats.asp

23 years, 7 months

PDP-11/53

by pete＠dunnington.u-net.com

On May 18, 17:32, Dave McGuire wrote: > On May 18, Pete Turnbull wrote: > > or 11/83 might work. I never used an 11/53 much, but from what I remember > > it's pretty much like other 11/73+ or 11/83 boards, just with memory on it > > as well as SLUs and bootstrap etc. I've no doubt someone else (Megan? > > Allison? others?) can expand on the differences. > > I believe the memory on the 11/53 board can be accessed much faster > than memory on the qbus, as well. Yes, I believe so. Anyone know *how much* faster? I don't think it was all that much faster than PMI memory. And I think the /53 *doesn't* work with PMI, which the /73 and /83 do (only the /83 was supported to use it, though). -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

Exidy Sorcerer: Next problem

by pete＠dunnington.u-net.com

On May 17, 22:10, Louis Schulman wrote: > OK, the power supply works! I have power on the motherboard. Now on > to the next problem. > > When attached to a composite monitor, I get video, but it is a > rolling/pulsing screen. Yes, I have the sync set to 60 Hz. I've seen that happen on Mark 1's where the sync isn't well matched to the monitor's needs and it couldn't lock. That seemd to happen with 50Hz versions and certain monitors, due to the timing of the sync pulse relative to the start of frame. Since this is a Mark 2 and I assume you're using it at 60Hz, I doubt that's the problem. Does switching between the 50Hz and 60Hz settings make a difference? If so, there's probably something wrong with the timing. Looking at the schematic, VSYNC is generated by the counters and multiplexers at 13A, 19B, 20B and 21B, and the 74LS74 flipflops at 18A and 18B. The 50Hz/60Hz switch controls the multiplexers at 13A and 19B, and they choose the reload values for the counters at 20B and 21B. You should see a high multiple (I'm too lazy to work out the frequency :-)) of 60Hz at 21B pin 15 and a lower multiple at 20B-15. That in turn feeds the LS74 at 18B, via the gate at 16A, and the VSYNC signal comes out of 18B-5. If you have a scope, that will tell you if the signal looks about right, if not, but you have a logic probe, at least you can look for 60Hz pulses. If it's extreme, perhaps the vsync isn't getting to the video socket. It's mixed by ORing it [1] with the HSYNC in the LS32 at 9B (pin 9 is VSYNC, 10 is HSYNC, 11 is composite). The composite sync is buffered by by an LS04 at 10H (in pin 10, out pin 11) and then via R59 is mixed with the video data (via R58) to the base of the video transistor. [1] which is what causes the problem for some 50HZ monitors; the HSYNC is effectively lost during the VSYNC pulse, which is very close to the first used scan line, so the top few lines of the screen tend to tear. > So, can you supply a troubleshooting procedure to find where the > problem lies? Again, keep in mind that this is a Sorcerer II (with > apparently 32K in Rows 2 and 3, is this the proper configuration)? Two rows is quite normal -- if the ICs are 4116 or equivalent you have 32K; if they're 4104 or equivalent you have 8K. I think you mean rows B and C (look for the numbers at the edge of the board). Physical row C is actually "row 1" or bank 1 as far as the RAM decode is concerned, and row B is bank 2. Row A is bank 3. The banks have to be filled in order 1,2,3 (rows C,B,A). So, yes, your setup is normal. If you can read the screen display, BASIC will tell you how much RAM is free after it initialises. If you don't have BASIC, the monitor ROM will tell you the address of the top of RAM after it initialises. -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

PDP-11/53

by pete＠dunnington.u-net.com

On May 18, 14:06, Eric Dittman wrote: > So, does any here have a source for bootable ROMs > for this CPU? The standard (as far as I know -- the ones I have came from a microPDP-11/53 in a BA23 case) boot ROMs are 23-261E5 and 23-263E5. I seem to have accidentally left binary images in my DECROMs directory at www.dunnington.u-net.com/public/ :-) -- Pete Peter Turnbull Network Manager University of York

23 years, 7 months

PDP-11/53

by mcguire＠neurotica.com

On May 18, Pete Turnbull wrote: > The standard (as far as I know -- the ones I have came from a > microPDP-11/53 in a BA23 case) boot ROMs are 23-261E5 and 23-263E5. I seem > to have accidentally left binary images in my DECROMs directory at > www.dunnington.u-net.com/public/ :-) Eric, do you have the facilities to burn these EPROMs? If not, I can help you. Feel free to contact me. -Dave McGuire

23 years, 7 months

PDP-11/53

by mcguire＠neurotica.com

On May 18, Pete Turnbull wrote: > or 11/83 might work. I never used an 11/53 much, but from what I remember > it's pretty much like other 11/73+ or 11/83 boards, just with memory on it > as well as SLUs and bootstrap etc. I've no doubt someone else (Megan? > Allison? others?) can expand on the differences. I believe the memory on the 11/53 board can be accessed much faster than memory on the qbus, as well. -Dave McGuire

23 years, 7 months

PDP-11/34 on eBay... NOT... NOT

by jss＠ou.edu

It seems that someone told the seller his PDP-11/34 didn't have CPU cards. The seller ended the auction and relisted, this time with a bullet point saying "Sorry there are no CPU cards". -- Jeffrey S. Sharp jss(a)ou.edu

23 years, 7 months

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test-drb May 2001