From: e...@infinet.com (Ethan Dicks) Newsgroups: alt.sys.pdp8 Subject: What are the differences between variants of the KK8E timing board (M833/M8330)? Date: 18 Feb 2003 07:55:42 -0800 I am trying to get back to resurrecting my -8/e. Having at last fixed the troublesome circuit breaker, I can power it on and off as I please. It doesn't do much else at the moment, though. :-( While perusing Doug Jones' list at http://www.cs.uiowa.edu/~jones/pdp8/hard8e/modules.html I was reminded that there are several varieties of KK8E timing board. I must have parts from an older machine in my spares bin - I have an M833 and an M8330 (as well as an M8650 and an M865). I know that the M833 (and the M865) must have come from an older machine. The question is what is the actual difference between the M8330, the M8330-YA and M8330-YB? If this is an RTFM question, pointers to the right FM would be helpful. I'm still pondering how to debug the KK8E since I don't have enough extension cards to get the entire CPU raised up (nor any jumper cables that would allow me to raise up a single board at a time). Any helpful suggestions? Thanks, -ethan From: bob smith Newsgroups: alt.sys.pdp8 Subject: Re: What are the differences between variants of the KK8E timing board (M833/M8330)? Date: Wed, 19 Feb 2003 01:30:25 GMT The M833 was used in the original PDP8/e. If it has some green wires on it, it will work with the M8310, M8320, etc. The cycle time on the 8e was changed - the timing was slowed down and the proirity interrupt system was deleted before the 4 digit 8/e cards came out. Simple change to slow the clock, but to ensure the boards were all compatible, I think that was the major reason for the number change. M8650 uses the UART chip, the M865 uses an MSI implementation of the uart. Both work in an 8/e, m, f, a if you have the io address set correctly. hope this helps bob From: bob smith Newsgroups: alt.sys.pdp8 Subject: Re: What are the differences between variants of the KK8E timing board (M833/M8330)? Date: Wed, 19 Feb 2003 21:12:45 GMT Gerold Pauler wrote: > bob smith wrote: > >> The M833 was used in the original PDP8/e. If it has some green wires >> on it, it will work with the M8310, M8320, etc. >> The cucle time on the 8e was changed - the timing was slowed down > > > Don't know about that, the cycle time for an pdp8/e/f/m always was > 1,2 us for a fast cycle and 1,4 us for a slow cycle. > The M8330 is adjustable to slow cycle only (faciliating debugging) > but I think this is also true for the M833. > IMHO the M8330 is a ECO'ed M833. I am glad you don't know about that. However, I do. The timing was changed. I know. I was there. I had to redesign my options based on the timing change that Louis Klotz and Remo Vogelsang decided was necessary to fix the timing problem with large systems - 4 omnibus backplanes, two boxes. Yes. the 8330 incorportates the timing change. THe resson for the 8330 vice 833 was to ensure that the timing chnage, and the other subtle changes inthe cpu (M831 to 8310, 832 to 8320, etc) were all tied together. Yes, the 1.2ux and 1.4, plus the abilty of the I/O device to slow down the system even more if necessary in data break and I/O mode are there too. From: bob smith Newsgroups: alt.sys.pdp8 Subject: Re: What are the differences between variants of the KK8E timing board (M833/M8330)? Date: Wed, 19 Feb 2003 21:36:01 GMT Ethan Dicks wrote: > Gerold Pauler wrote in message news:<3E532C5...@gmx.net>... > >>bob smith wrote: >> >> >>>The M833 was used in the original PDP8/e. If it has some green wires on >>>it, it will work with the M8310, M8320, etc... >> > > Does anyone have that ECO information handy? You would have to look atthe original 8/e cpu schematics for the 833 and compare them to the 8330, the timing was the changed and slowed, it was a change in where the counter was tapped. We used some four bit counters tied together to generate the timing pulses, and by tapping one of the counters at a different bit, it was slowed down. Look at the omnibus spec at the TS and TP signal definitions. > > >>IMHO the M8330 is a ECO'ed M833. > > > I was under that impression, too, but I'm seeking to find _how_ it > was ECO'ed since I have an M833 and would like to be able to use > it in a semi-modern (so to speak) configuration. As I said previously, does it have a green or yellowish tinted wire a little to the left of the middle of the board on the chip side? if it does, that is the eco. > > Among the specific problems I've been trying to work around has been > debugging the KK8E without any core. I finally have enough H851s to > populate my CPU, one core stack and an my as-yet-untested RK8E, but > while doing extended debugging sessions last year, I had to resort > to putting the KK8E in my -8/a box so I could use an MSC8, the only > other OMNIBUS memory I have. I was concerned that the older card > would not be able to talk to the newer MOS memory. Now, the KK8e is faster than the KK8a. The cpu, for the e, consisting of the m8300, 8310, 8320, and 8330 will address 4k words only. YOu need the KM8e or the KT8A to go above 4K. THe KM8e is also the timeshare controller. Don't forget on an 8e, you have to have the busloads board, the m8320 in the last slot to ensure proper signal propogation. The 8a cpu has the bus loads built into the cpu. > > >>>M8650 uses the UART chip, the M865 uses an MSI implementation of >>>the uart. Both work in an 8/e, m, f, a if you have the io address >>>set correctly. >> >>I disagree, the M865 and M8650 are identical besides ECOs. > > > I disagree with _that_. My M865 has split-lugs for the 20mA TTY > cable and the M8650 has a 40-pin Berg connector that takes either > a TTY cable or an EIA (RS-232) cable. Additionally, I don't think > you can modify the device numbers from 03/04 on the M865 (no lugs > near the fingers of the board). From a _software_ standpoint, though, > the CPU can't tell an M865 from an M8650. Yeah, I double check this, the 865 is the split lug as you say,and the 8650 has the berg connector that allows auto select of current mode or rs232c. The 8655 is the uart version. I don't recall what number we gave the KL8M, added modem control to the KL8e family. From: "James P. Gonzalez" Newsgroups: alt.sys.pdp8 Subject: Re: What are the differences between variants of the KK8E timing board (M833/M8330)? Date: Sat, 22 Feb 2003 13:03:59 -0500 For 8E/F/M the M8330 would be an acceptable board. As you said the M835 was a real old variation in the very first 8E's. The M8330-YA and YB were very late revisions - the changes were primarily to be compatible with 8A boards/chassis since the 8E processor was used in the larger (20 Slot and 20 Slot/2 Box - PDP 8A's). The 8A CPU (M8315) was only used in the smaller chassis (12 Slots?) as it had no end of bus termination as required for the larger chassis or to add the expansion chassis.