TUHS

tuhs@tuhs.org

6420 discussions

by jnc＠mercury.lcs.mit.edu

> From: "Engel, Michael" <M.Engel(a)leedsbeckett.ac.uk> > The machine has a Multibus FD controller with its own 8085 CPU and a > uPD765, connected to a Toshiba 5.25" DD floppy drive (720 kB, 80 > tracks, 9 sectors of 512 bytes), the model identifier is DDF5-30C-34I > ... I couldn't find any information on that drive online, so I hesitate > to simply connect a more modern drive due to possible pinout differences. > ... > I also found out a bit more on the SMD disk controller. It seems to be > an OEM variant of the Micro Computer Technology MCT-4300 controller. > The only place I could find this mentioned was in a catalog of Multibus > boards on archive.org. > ... > So, if you happen to have any information on the Codata floppy > controller, the Toshiba floppy or the MCT-4300 SMD disk controller, I > would be happy to hear from you... I don't, but can I suggest the Classic Computers mailing list: http://www.classiccmp.org/mailman/listinfo/cctalk They seem to have an extremely deep well of knowledge, and perhaps someone there can help? (I'd rate the odds very high on the floppy drive.) Noel

10 years, 3 months

Codata progress update

by Engel, Michael

Hi, it's time for an update on our progress with the Codata machine. The serial interface problem was not caused by a defective transceiver chip (which I found out after buying a couple…), but by an extreme amount of noise on the (quite long and old) serial cable we used to connect the machine to the PC acting as a terminal. Using a USB to serial adapter and a short 9-to-25-pin adapter cable solved this problem. Well, try the obvious things first (using a scope helped). The second CPU board also works, so we could build a complete second machine with our spare boards if we have another multibus backplane... We could get the machine up and booting from the first 8" hard disk last Friday. Luckily, an old version of Kermit was installed and we were able to transmit a large part of the root file system from single user more - especially the Unix kernels, driver sources, the build directories for the kernel, include files and the build directory for the standalone boot floppies. All with a speed of 500 bytes/s (9600 bps serial line minus kermit overhead). cksum was used to confirm that the files were transferred correctly (this was the only checksumming tool that was available on the Codata, I didn't want to mount the fs read-write and compile software before completing the backup). I had to shut the machine down on Friday evening (security policy that kicks you out of the building here), since I didn't want to leave it running unattended over the weekend. Unfortunately, the disk seems to have developed a bad sector in the autoconfiguration region (the system seems to be quite modern in this respect). The kernel can be booted successfully, but it refuses to mount the root fs, complaining about a timeout. There seems to be a complete root file system on the second disk (the firmware is able to read files from the disk, but it doesn't offer a feature to list directories…), but the kernel on the second disk also is hardwired to mount its root fs from the first disk. Trying to connect disk 2 as disk 1 resulted in a non-booting system... The good news is that both root file systems seem to be reasonably intact so far, I can read text files from the boot monitor. So our next step to backup the rest of the system is to build an emergency boot floppy. At the moment, however, the Codata refuses to talk to its floppy drive. The machine has a Multibus FD controller with its own 8085 CPU and a uPD765, connected to a Toshiba 5.25" DD floppy drive (720 kB, 80 tracks, 9 sectors of 512 bytes), the model identifier is DDF5-30C-34I (printed on the motor assembly). I couldn't find any information on that drive online, so I hesitate to simply connect a more modern drive due to possible pinout differences. I also found out a bit more on the SMD disk controller. It seems to be an OEM variant of the Micro Computer Technology MCT-4300 controller. The only place I could find this mentioned was in a catalog of Multibus boards on archive.org. It has its own driver (cd.c), there is a separate one for the Interphase 2180 and an additional one for the Codata MFM controller. So, if you happen to have any information on the Codata floppy controller, the Toshiba floppy or the MCT-4300 SMD disk controller, I would be happy to hear from you... -- Michael

10 years, 3 months

Re: [TUHS] early cc variable and function names

by jnc＠mercury.lcs.mit.edu

> From: Greg 'groggy' Lehey <grog(a)lemis.com> > This is really an identifier issues Probably actually a function of the relocatable object format / linker on the machines in question, which in most (all?) cases predated C itself. > it's documented in K&R 1st edition, page 179: Oooh, good piece of detective work! Noel

10 years, 3 months

early cc variable and function names

by Mark Longridge

Hi folks, I've been looking at Unix v5 cc limitations. It seems like early cc could only use variable and function names up to 8 characters. This limitation occurs in v5, v6 and v7. But when using the nm utility to print out the name list I see function test1234() listed as: 000044T _test123 That seems to suggest that only the first 7 characters are significant, but when looking at other sources they stated that one can use up to 8 characters. I hacked up a short program to test this: main() { test1234(); test1235(); } test1234() { printf ("\nWorking"); } test1235() { printf ("\nAlso working"); } This generated: Multiply defined: test5.o;_test123 So it would seem that function names can only be 7 characters in length. I am not sure if limitations of early cc were documented anywhere. When I backported unirubik to v5 it compiled the longer functions without any problem. Did anyone document these sorts of limitations of early cc? Does anyone remember when cc started to use function names longer than 7 characters? Mark

10 years, 3 months

Re: [TUHS] early cc variable and function names

by jnc＠mercury.lcs.mit.edu

> From: Mark Longridge <cubexyz(a)gmail.com> > It seems like early cc could only use variable and function names up to > 8 characters. > This limitation occurs in v5, v6 and v7. > ... > That seems to suggest that only the first 7 characters are significant, > but when looking at other sources they stated that one can use up to 8 > characters. The a.out symbol tables use 8-character fields to hold symbol names. However, C automagically and unavoidably prepends an _ to all externals (I forget about automatics, registers, etc - too tired to check right now), making the limit for C names 7 characters. > I am not sure if limitations of early cc were documented anywhere. I remember reading the above. Other limits... well, you need to remember that C was still changing in that period, so limits were a moving target. > When I backported unirubik to v5 it compiled the longer functions > without any problem. ISTR that C truncated external names longer than 7 characters. Probably the ones in that program were all unique within 7, so you won. > Did anyone document these sorts of limitations of early cc? I seem to recall at least one document from that period (I think pertaining to the so-called 'Typesetter C') about 'changes to C'. Also, I have started a note with a list of 'issues with C when you're backporting V7 and later code to V6', I'll see if I can dig them out tomorrow. Noel

10 years, 3 months

3BSD/32V: 2 RP06 (SIMH)

by Cory Smelosky

Afternoon, # /etc/mkfs /dev/rrp1g 145673 isize = 65488 m/n = 3 500 write error: 2 # file rp0g rp0g: block special (0/6) # file rp1g rp1g: block special (0/14) # file rp0a rp0a: block special (0/0) # file rp1a rp1a: block special (0/8) # file rrp0a rrp0a: character special (4/0) # file rrp1a rrp1a: character special (4/8) # file rrp0g rrp0g: character special (4/6) # file rrp1g rrp1g: character special (4/14) DESCRIPTION Files with minor device numbers 0 through 7 refer to various portions of drive 0; minor devices 8 through 15 refer to drive 1, etc. The origin and size of the pseudo-disks on each drive are as follows: What am I forgetting? I have an image attached, I have modified hp.c to have NHP as 2. Is it conflict between rp.c and hp.c? (I patched hp.c to have NHP 2 after patching NURP in rp.c to be 2). -- Cory Smelosky http://gewt.net Personal stuff http://gimme-sympathy.org Projects

10 years, 3 months

Re: [TUHS] early cc variable and function names

by jnc＠mercury.lcs.mit.edu

> From: jnc(a)mercury.lcs.mit.edu (Noel Chiappa) >> Did anyone document these sorts of limitations of early cc? > I seem to recall at least one document from that period (I think > pertaining to the so-called 'Typesetter C') about 'changes to C'. > ... > I'll see if I can dig them out tomorrow. OK, there are three documents which sort of fall into this class. First, there is something titled "New C Compiler Features", no date, available here: http://minnie.tuhs.org/cgi-bin/utree.pl?file=Interdata732/usr/doc/cdoc/news… no date, but it appears to describe an early version of the so-called 'Typesetter C', mentioned in other documents, so this would be circa 1976 or so. There is a second document, untitled, no date, which I have not been able to locate online at all. I scanned my hard-copy, available here: http://ana-3.lcs.mit.edu/~jnc/history/unix/CImprovements1.jpg .. http://ana-3.lcs.mit.edu/~jnc/history/unix/CImprovements5.jpg >From the content, it seems to be from shortly after the previous one, so say, circa 1977. Sorry about the poor readability (it looked fine on the monitor of the machine my scanner is attached to); fudging with contrast would probably make it more readable. When I get the MIT V6 Unix tapes read (they have been sent off to a specialist in reading old tapes, results soon, I hope) I might be able to get more info (e.g. date/filename), and machine-readable source. Finally, there is "Recent Changes to C", from November 15, 1978, available here: http://cm.bell-labs.com/cm/cs/who/dmr/cchanges.pdf which documents a few final bits. There is of course also Dennis M. Ritchie, "The Development of the C Language", available here: http://cm.bell-labs.com/who/dmr/chist.html which is a good, interesting history of C. > Also, I have started a note with a list of 'issues with C when you're > backporting V7 and later code to V6' I found several documents which are bits and pieces of this. http://ana-3.lcs.mit.edu/~jnc/history/unix/C_Backport.txt http://ana-3.lcs.mit.edu/~jnc/history/unix/V6_C.txt Too busy to really clean them up at the moment. Noel

10 years, 3 months

ISPS

by luca.nini

Back in the 80s in my University days I was using ISPS (Instruction Set Processor Simulator if I remember correctly ) a software tool To simulate CPU. It ran on a Vax with BSD 4.2. I have been unable to find any reference to It on the Internet . Do someone on this list know anything offerte this software ? Thanks Luca

10 years, 3 months

Re: [TUHS] Getting Unix v5 to talk

by jnc＠mercury.lcs.mit.edu

> From: Mark Longridge > Fortunately we have the file /usr/sys/dmr/vs.c to look at so this could > be compiled into the kernel although I haven't done this as yet. The vs.c seems to be a Votrax speech synthesizer hooked up to a DC11 interface. Do any of the simulators support the DC11? If not, adding the driver won't do you much good. Noel PS: I seem to recall the DSSR group on the 4th floor at LCS actually had one of these, back in the day. The sound quality was pretty marginal, as I recall!

10 years, 3 months

Getting Unix v5 to talk

by Mark Longridge

Thanks to the efforts of Jonathan Gevaryahu I have managed to get the Unix v5 speak utility to compile and execute. All this was done using the simh emulator emulating a PDP-11/70. Jonathan managed extract enough of speak.c to reconstruct it to the point it could be compiled with v5 cc. I believe it was necessary to look at speak.o to accomplish this. Jonathan also states that there are more interesting things that could possibly be recovered from v6doc.tar.gz One can look at speak.c source here: http://www.maxhost.org/other/speak.c Now had we have speak compiled we can go a bit further: cat speak.v - | speak -v null generates speak.m from ascii file speak.v speak speak.m computer !p (prints out phonetics for working word) which outputs: ,k,a0,m,p,E2,U1,t,er,-1 ctrl-d exits Looking at speak.c we can see that it opens /dev/vs. Fortunately we have the file /usr/sys/dmr/vs.c to look at so this could be compiled into the kernel although I haven't done this as yet. speak.c looks like Unix v5 era code. My understanding is that Unix v5 appeared in June 1974 and the comments say 'Copyright 1974' so it seems plausible. I'm intrigued by the possibility of getting Unix v5 to talk. Mark

10 years, 3 months

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TUHS