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Re: Computhink Eagle 32 - software, docs, info?

by Wouter de Waal

Hi all Chris gave me a copy of the boot ROM and I played around with it a bit. >I threw the 4KB of boot ROM in Ghidra and confirmed a couple things: > >- At boot, ROM is mapped to 0, and then remapped either by a write >to the location or by a cycle counter: The initial stack pointer at >0x0 is 0x0001fffe and the initial program counter at 0x4 is >0x00ffc026, indicating the ROM is normally located at 0x00ffc000. >- The ROM freely interchanges addresses in the >0x00ffc000..0x00ffffff range and addresses in the >0xffffc000..0xffffffff range, which is annoying to deal with in Ghidra. The code takes advantage of the 68000 sign-extend on absolute short addressing mode, like move.b #$00, $8011. IDA correctly disassembles this to "move.b #0,($FF8011).w". I assume Ghidra if sign-extending it all the way to FFFF8011? >- I/O devices appear to be in the 0x00ff8000..0x00ffbfff range, all >of the devices accessed via the bootstrap seem to be barely above 0x00ff8000. >- Only NMI, bus error, interrupt 2, and interrupt 5 are set up by >the bootstrap. Yup. >- The bootstrap is very bare-bones but still has a bunch of >indirection in it; itâs obviously written in assembly, but it does >seem to have parameterization so it may support both console and serial I/O. I suspect either some low-level high-level language, or massive use of macros (which is in effect a low-level high-level language :-) Code like: ; Called with A6 pointing to a length and a string address 00FFCA4C : 48E7 8080 MOVEM.L D0,A0,-(A7) 00FFCA50 : 3016 MOVE.W (A6),D0 ; length 00FFCA52 : 48C0 EXT.L D0 00FFCA54 : 206E 0002 MOVEA.L +2(A6),A0 ; pointer to string 00FFCA58 : 508E ADDQ.L #8,A6 ; clear stack 00FFCA5A : 5380 SUBQ.L #1,D0 00FFCA5C : 6B0E BMI $00FFCA6C ; done 00FFCA5E : 518E SUBQ.L #8,A6 ; make space on stack again 00FFCA60 : 1D58 0001 MOVE.B (A0)+,+1(A6) ; one character on stack 00FFCA64 : 4EB8 C566 JSR $00FFC566 00FFCA68 : 51C8 FFF4 DBF D0,$00FFCA5E ; loop 00FFCA6C : 4CDF 0101 MOVEM.L (A7)+,D0,A0 00FFCA70 : 4E75 RTS >I suspect that I can figure out from the pattern of I/O accesses >which devices are at which address in the memory map, at least if I >bring up an emulation in MAME. That should at least allow writing >new code for it, and _maybe_ even figuring out which CRT controller >the video hardware uses and where in the memory map it is. (I >suspect the 6845 and/or 6847 just from the time period, but who >knows? Gotta see what it actually do when trying to show the âIPL >IN PROGRESSâ string contained in the ROM, or one of the couple >error strings) > Chris

1 year, 6 months

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Looking for a DG manual

by Peter Ekstrom

Hello, Does anyone have a PDF of the AOS/VS Systems internals reference manual by chance? Thanks, Peter

1 year, 6 months

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More ALGOL-68

by Mark Kahrs

I remember circa 1977 CMU had a PDP-11 compiler for '68 with an extensive runtime component. I presume the sources are lost. Peter Hibbard was the guy responsible if I recall.

1 year, 6 months

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Re: More ALGOL-68

by Paul McJones

> On Jan 6, 2024,Mark Kahrs <mark.kahrs(a)gmail.com <mailto:mark.kahrs@gmail.com>> wrote: > > I remember circa 1977 CMU had a PDP-11 compiler for '68 with an extensive > runtime component. > I presume the sources are lost. > > Peter Hibbard was the guy responsible if I recall. Yes, Peter was the author, and he also sponsored a corresponding ALGOL68 subset. My “history of Algol” web site has information here: https://www.softwarepreservation.org/projects/ALGOL/algol68impl/#ALGOL_68S In particular, there is a snapshot with binaries and some assembler files here: https://www.tuhs.org/Archive/Applications/Algol_68/ <https://www.tuhs.org/Archive/Applications/Algol_68/> and a later rewrite by C. H. Lindsey in the Amsterdam Compiler Kit here: https://github.com/davidgiven/ack/tree/default/lang/a68s https://www.clerew.man.ac.uk/#ALGOL%2068 See my web site cited above for additional information, papers, and documentation. Paul

1 year, 6 months

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86-DOS disks...

by geneb

For those interested, I've imaged a couple of super rare (actually rare, not "ebay" rare) original 86-DOS disks. https://archive.org/details/86-dos-version-0.1-c-serial-11-original-disk https://archive.org/details/86-dos-version-0.34-c-serial-221-original-disk Both will boot under simh. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://scarlet.deltasoft.com - Get it _today_!

1 year, 6 months

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Anyone have a D1 deck?

by Jim Brain

https://entertainment.slashdot.org/story/23/12/30/0151241/documentarians-se… -- Jim Brain brain(a)jbrain.com www.jbrain.com

1 year, 6 months

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RIP: Software design pioneer and Pascal creator Niklaus Wirth

by Liam Proven

Evangelist of lean software and devisor of 9 programming languages and an OS was 89 https://www.theregister.com/2024/01/04/niklaus_wirth_obituary/ The great man has left us. I wrote an obituary. -- Liam Proven ~ Profile: https://about.me/liamproven Email: lproven(a)cix.co.uk ~ gMail/gTalk/FB: lproven(a)gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven IoM: (+44) 7624 277612: UK: (+44) 7939-087884 Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053

1 year, 6 months

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IBM 5110 IMFs

by Christian Corti

Does anyone here has an actual IMF file (Internal Machine Fix) for the IBM 5110? Not the file called "IMF" on the Customer Support Functions disk/tape, but a real fix. File type should be 23. I am trying to figure out how the patch mechanism works. The IMF is supposed to be loaded with the LOADER utility. Christian

1 year, 6 months

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Re: Computhink Eagle 32 - software, docs, info?

by Wouter de Waal

Hi Chris and all >- No video board, whether text or graphics > >Since thereâs no video board in the system, and a couple of cables >internally that arenât attached to anything, I expect it was >removed by a previous caretaker. This is sad because without one >itâs unlikely to come up, not that anyone has found any software >for it. On the other hand, there are zero PALs, so both full reverse >engineering and maintenance should be straightforward. I've scanned the press releases and adverts that come up on Google and I'm going to wager it was meant to be used with one or two terminals. Nowhere do they mention a display, and the adverts show a box sitting next to a terminal. Send me a copy of the ROM binary please? W

1 year, 6 months

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VAX 4000-200 in BA215 chassis. Can I install a KFQSA card and connect the cabinet disks to it?

by thomasdzubin＠gmail.com

I have a couple of VAX 4000-200 boxen running OpenVMS. I want to try out NetBSD on them but NetBSD does not support the SHAC DSSI controller on the KA660 CPU card. However NetBSD *DOES* support the KFQSA DSSI controller which I have a few of in my VAX 3800s. Can I install the KFQSA card in my 4000-200, disconnect the internal disks from the SHAC and connect the disks to the KFQSA thereby allowing NetBSD to run? Has anyone done anything like that? Happy 2024 everyone! Thomas Dzubin Calgary, Vancouver, or Saskatoon CANADA

1 year, 6 months

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