Date: Mon, 4 May 92 15:31:25 EST From: Dwight D. McKay (The Moderator) Reply-To: Suns-at-Home@orchestra.ecn.purdue.edu Subject: Suns-at-Home Digest V5 #19 To: Suns-at-Home-List Suns-at-Home Digest Mon, 4 May 92 Volume 5 : Issue 19 Today's Topics: Need MD21 pseudo Sun-3 saga Sun 3-100 saga ... a solution +--------------------------------------------------------------------+ | Submissions: suns-at-home \ @orchestra.ecn.purdue.edu | | Requests: suns-at-home-request > -- or -- | | Archives: suns-at-home-archives / ...rutgers!pur-ee!... | +--------------------------------------------------------------------+ ---------------------------------------------------------------------- Date: Mon, 27 Apr 92 18:42:57 -0400 From: dae@world.std.com (Dwight A Ernest) Subject: Need MD21 To: suns-at-home@ecn.purdue.edu Hi. I seem to have a faulty MD21 ESDI-SCSI controller on myu home 3/50. If you know of a good inexpensive source for these boards, or have one for sale yourself, I want to hear from you. Regards, --Dwight A. Ernest KA2CNN dae@world.std.com Publishing System Software and Networking Consultant 171 East Street #373 Methuen, MA 01844 USA Join the Electronic Frontier Foundation: eff@eff.org ------------------------------ Date: Sun, 3 May 92 12:45:21 +0200 From: P.H.A.Venemans@research.ptt.nl (Venemans P.H.A.) Subject: pseudo Sun-3 saga To: Suns-at-Home@orchestra.ecn.purdue.edu In SAH Vol 5 / Issue 18, Bill Rankin (wtr@bromo.att.com) wrote he was becoming quite desperate in getting his 3/160 to work in a 2/50 cabinet. Although I have no experience with the 3/160, his problems appear to be quite similar to the ones I had to solve when I mounted a 3/60 board in a 2/50 cabinet (same symptom: no video). Since my findings might be useful to some of you, I give here a summary of the things that were needed to get the thing working. Please contact me if you need more detailed information. The original 2/50 is a VME bus machine. It contains 2 large PCBs, each with 3 DIN-41612 (eurocard) connectors on it and there is a small, two slot backplane in the cabinet. Two of the connectors on each PCB are used for the "real" VME bus: they carry the usual data, address and control lines. The third connector is used for power. The 3/60 is a single board computer that lacks an external VME bus. The only connector on it (DIN-41612 too) is for the power. The 3/60 board slides easily in a 2/50 cabinet and its power connector (P96) fits nicely into the power connector on the 2/50 backplane. But things are not that easy.... The 2/50 backplane power connectors (P103/P203) carry: 5 V pins a1...a25, max 20 A GND pins c1...c25 12 V pins a26,a27,c26,c27, max 4 A -12 V pins a28,a29,c28,c29, max 0.5 A BUT... the 3/60 also needs : -5.2 V pins a30...a32, c30...c32 and that is NOT available on the 2/50 backplane. The point is that on the 3/60 a substantial part of the video circuit is build with ECL (10K) logic. On the 2/50, there are only 2 ECL chips in the video circuit and they are powered by means of a local, on board linear power regulator that makes -5.2 V from the available -12 V. For a 3/60, this is not possible since the ECL draws around 0.6 A, too much for the 0.5 A -12 V supply. The only way out is to provide an additional power supply for -5.2 V . The way I solved this is to build a small switching power converter that converts +12 V into -5.2 V and that fits into the unused second slot of the 2/50 backplane (it gets its +12 V from the +12 V pins and inserts the -5.2 V on the formerly unused -5.2 V pins). The 12 V power is not used at all in a 3/60 (it is only fed to the connector for an external ethernet tranceiver) so the full 4 A is available for this purpose. An alternative (and easier) solution would be to wire an external -5.2 V power supply to the -5.2 V pins on the backplane (a conventional 5.0 V supply might also be sufficient). The second problem is the monitor. The 2/50 CPU generates an ECL level video signal, and a 2/50 monitor is an ECL monitor. My monitor (540-1062-01) turned out to be switchable between ECL and TTL levels. A 3/60 also generates ECL video. But, there was a small problem with the precise signal levels. In my monitor, the 2 balanced video lines (pins 1 and 6 on the 9 pin sub-D connector) were not terminated properly. Officially, an ECL line should be terminated by a 50 ohm resistance to -2 V. Instead, they were terminated by a 82 ohm resistor to -5.2 V. When calculating the resulting signal levels, this makes not much difference, but it was sufficient to prevent the 3/60 video, which uses a different driver IC, from driving the ECL receiver properly. Result: a very white screen. The solution was to add two 180 ohm terminating resistors, from the video lines to the +5 V supply (for instance: pin 9 on the 10125 receiver IC). In combination with the existing 82 ohm resistor, this is equivalent to a 56 ohm termination to -2 V. This small modification does not affect operation with the original 2/50 board. The horizontal (pin 3, pin 7 return, 16 us) and vertical (pin 4, pin 8 return, 15 ms) sync lines are TTL and give no problems. For reference, the part numbers of the components I described are: 3/60 CPU 501-1207 2/50 CPU 501-1141 2/50 backplane 270-1042-02 2/50 monitor 540-1062-01 2/50 video board in monitor 501-1056-03 Rev 50 --- Pieter H.A. Venemans - Royal PTT Netherlands N.V. - PTT Research P.O.Box 421 - 2260 AK Leidschendam - the Netherlands Email: P.H.A.Venemans@research.ptt.nl phone: +31 70 3325556 ------------------------------ Date: Mon, 27 Apr 92 18:17:46 MST From: Thomas Weihrich Subject: Sun 3-100 saga ... a solution To: Suns-at-Home@ecn.purdue.edu HI ! Here's a proposed solution for the 3/1?? trouble ... I cannot promise that it works, but at least one might give it a try. Make sure that you have the on board mono framebuffer activated in your boot prom. Look at the address 0x01f. There should be a 0x00 to activate your console fb. Boot up. enter the /dev-directory. do a MAKEDEV bw2 and a MAKEDEV fb you can also do this using the mknod command this is what you need: crw------- 1 root 22, 0 Feb 6 1991 fb crw------- 1 root 27, 0 Feb 6 1991 bwtwo0 Hope this gets you going. The BWTWO is gonfigured in the GENERIC kernel. Regards Thomas ------------------------------ End of Suns-at-Home Digest ******************************