Previous Thread
Next Thread
Print Thread
Page 2 of 3 1 2 3
Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105651
05/19/16 08:19 PM
05/19/16 08:19 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
This will be in SIMH first. I would certainly like to see it in MAME too, but it has to work reasonably well first.

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105697
05/22/16 12:03 PM
05/22/16 12:03 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
A braindump on the Blit and 5620.

:
: Blit
:

Wikipedia -- basic info, links to FAQ and video demo (https://www.youtube.com/watch?v=emh22gT5e9k, found in http://doc.cat-v.org/bell_labs/blit/).

Apparently, 'Blits (with 68000 CPUs) came with copious hardware and software documentation (on-line, even!)' (usenet post) but none of that is online; there are a few paywalled articles though:

"The UNIX system: The blit: A multiplexed graphics terminal" (AT&T Bell Laboratories Technical Journal, Volume 63, Issue 8)
"The UNIX system: Debugging C programs with the blit" (ditto)
"Implementation of the blit debugger" ['joff is an asynchronous, source-level, break-and-examine debugger for C programs running on the Blit'] (Software: Practice and Experience, Volume 15, Issue 2, pages 153–168, February 1985)
reference to "The Blit Debugger" articles -- https://blogs.oracle.com/mws/entry/once_blitten
reference to att.blit usenet group [not online] and to "University of Toronto has developed and is currently ['1986] using a 5620(blit) terminal emulator in a ROM cartridge for the [Atari] 520ST" + "Dave Galloway at the U of Toronto Computer Science Research Centre is the person to talk to."

.
. Dot Mapped Display 5620
.

Engineering drawings (include schematics + technical manual) are online -- http://www.brouhaha.com/~eric/retrocomputing/att/5620/att5620_eng.pdf
Computer History Museum has a physical copy -- http://www.computerhistory.org/collections/catalog/102724228
Technical manual for the CPU is at Bitsavers -- http://bitsavers.trailing-edge.com/pdf/w...anual_Jan85.pdf

Other docs were published (306-XXX is AT&T documentation "Select Code") -- these are not online. Manuals for the follow-on models are on bitsavers in http://bitsavers.trailing-edge.com/pdf/att/630_mtg/ and http://bitsavers.trailing-edge.com/pdf/att/730/.

306-120 5620 Dot-Mapped Display, User Guide
306-122 5620 Dot-Mapped Display : software developer application guide.
306-142 5620 DMD Rel. 2.0 Application Development Guide
306-144 5620 DMD Rel. 2.0 Reference Manual
??? 5620 Dot Mapped Display Terminal Service Shop Manual [= AT&T Teletype Manual 625 (Issue 1, July 1984)]

Hardware details that matter for emulation (page numbers are from att5620_eng.pdf):

cpu: Bellmac 32A (WE 32001) or 32B (WE 32100) at 7.2 mhz (xtal 28.8 mhz div 4).
p. 1-1, 1-2
23-bit address bus (8 MB addressable)
p. 1-10
no alignment traps
p. 1-5

memory map:
Code:
static ADDRESS_MAP_START(dmd5620_mem, AS_PROGRAM, 32, dmd5620_state)
        ADDRESS_MAP_UNMAP_HIGH
        AM_RANGE(0x000000, 0x01ffff) AM_ROM
        AM_RANGE(0x200000, 0x20003f) AM_DEVREADWRITE8(DUART_TAG, mc68681_device, read, write, ???)   // Port A: host, Port B: keyboard/printer
        AM_RANGE(0x300000, 0x3000ff) AM_NOP     // 8530 SCC on optional I/O board
        AM_RANGE(0x400000, 0x400003) AM_NOP     // mouse X/Y data
        AM_RANGE(0x500000, 0x500001) AM_NOP     // display starting addr
        AM_RANGE(0x600000, 0x601fff) AM_READWRITE8(nvram_r, nvram_w, ???)    // BBRAM
        AM_RANGE(0x700000, 0x7fffff) AM_RAM     // 256K or 1M
ADDRESS_MAP_END


800x1024 bitmap, 1024x1067 raster, 32 MHz dot clock, 60 Hz field clock
p. 1-20
hsync freq
32.01 kHz
vblank duration
704 ms?

two levels of interrupts, no autovector
p. 1-4
sources of high level [ipl 15] interrupt:
rs232c send buffer ready for data "INT232R";
rs232c receive data available "INT232S";
"PIO00"
p. 1-8
sources of low level [ipl 14] interrupt:
keyboard receive data available;
mouse buttons changed/vblank (60 Hz)/rs232c "INTM0";
cts/dsr/dcd changed;
"PIO01"
p. 1-8

404381 DUART [similar to SCN2681, MC68681] -- clock unknown
p. 1-24
keyboard rx speed fixed at 4800 baud
p. 1-25
interrupts the CPU via INT output ("INTM0" signal) and via OP4..OP6 ("INT232R", "INTKBD" and "INT232S" signals)
p. 1-25
controls the 'reverse video' bit
p. 1-24

ROMs:

Firmware on motherboard -- not dumped, but images of 2.0 variant are in 5620rom.cpio.Z:src/xt/layersys/roms/save; these do not exactly match symbol tables in 5620rom.cpio.Z:src/xt/layersys/rdpatch/lsys.nm.2.0
version 1.0 aka "8;7;1"
version 1.0b(?) aka "8;7;2"
version 1.1 aka "8;7;3"
version 2.0 aka "8;7;5" -- 'corresponds to AT&T 5620 DMD host software Release 2.0'
PALs on motherboard
not dumped
Firmware of "MOS chip" in keyboard
not dumped

.
. WE32000 and 3B2
.

https://en.wikipedia.org/wiki/Bellmac_32
https://en.wikipedia.org/wiki/3B_series_computers

https://github.com/sethm/3b2_rom/blob/master/we32dis.rb
disassembler

.
. Relevant software and stuff
.

Online:

Host software, SDK (SGS -- Software Generation System), demo apps
http://www.brouhaha.com/~eric/retrocomputing/att/5620/
AT&T DMD 5620 series FAQ -- February, 1996
ftp://ftp.cs.utk.edu/pub/shuford/terminal/att_5620_faq.txt
games & programs formerly at ftp://little.nhlink.net/pub/att/dmd/
http://yahozna.dyndns.org/computers/software/3b2/misc/little.nhlink.net/dmd/
dmdtetris
https://groups.google.com/forum/message/raw?msg=comp.terminals.tty5620/H92XPIjyq0I/LroppcP2y7gJ
swarm
https://groups.google.com/forum/message/raw?msg=comp.terminals.tty5620/QIYRGuJilqo/Es5728Nm350J
dmdtobdf
https://groups.google.com/forum/message/raw?msg=comp.fonts/9bZlR6ELwt4/fRg6ZWeK7TQJ
dmdp clone
https://groups.google.com/forum/message/raw?msg=net.sources/VyRhPodF9o8/mB4jOzpYvogJ
dvidmd (via umddvi via CTAN)
http://mirror.hmc.edu/ctan/dviware/umddvi/

crabs
.../little.nhlink.net/dmd/5620/crabs.m.z
http://9fans.net/archive/2008/01/133 via archive.org
http://research.swtch.com/crabs
http://lucacardelli.name/Papers/Crabs.pdf
http://lucacardelli.name/Papers/Crabs%20%28History%20and%20Screen%20Dumps%29.pdf
http://man.cat-v.org/unix_8th/9/crabs
At Bell Labs work is play and terminal diseases are benign (Scientific American, September 1985, paywalled)
gebaca
.../little.nhlink.net/dmd/5620/gebaca.m.z -- runs standalone i.e. not under layers
cent (a centipede game)
.../little.nhlink.net/dmd/5620/cent.m.z
postcard (a neat French post-card with lots of action for your demo file)
.../little.nhlink.net/dmd/5620/postcard.z

Not online:

AT&T UNIX System ToolChest's "dmd-pgmg" package [includes "sam" text editor and "myx" terminal emulator]
https://groups.google.com/forum/#!search/%22dmd-pgmg%22/net.unix/jLMU939d7is/KyCJCAYtFrMJ
vismon and zunk, for the Blit
https://en.wikipedia.org/wiki/Vismon
https://en.wikipedia.org/wiki/Zunk

nuke the smileys
via https://groups.google.com/forum/#!search...z0/tu33IAGjrrYJ)
maxwell (via https://groups.google.com/forum/#!original/comp.unix.questions/zmac3VxmLa8/lMIEPTG8-fQJ)
Quote:

'It created a box with two halves, with white and black balls bouncing
around inside. There was a door between the two. By clicking on the door you
could open it or shut it. If you were bored you could play maxwell's daemon,
and get all the black balls on one side, and all the white on the other (unless
you got a court order to desegregate :-). Another possibility was to get all
the balls on one or the other side. Oh - the black and white balls moved at
different speeds, and when collisions occurred, balls could change from one
color to the other.'

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105698
05/22/16 01:04 PM
05/22/16 01:04 PM
Joined: Mar 2001
Posts: 16,070
USA
R
R. Belmont Online content
Very Senior Member
R. Belmont  Online Content
Very Senior Member
R
Joined: Mar 2001
Posts: 16,070
USA
So are the 68k-version blit ROMs available too, or just the WE32K?

Also, based on the disassembly, the 3B2 POST is actually a WE32K torture test, so that's handy smile

Last edited by R. Belmont; 05/22/16 01:11 PM.
Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105699
05/22/16 01:53 PM
05/22/16 01:53 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
Only we32k, and it's not actually original, far as I can tell -- makes things a bit more interesting since symbols don't match the code after a certain point.

Seth says he's getting a 5620 soon so that could change.

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105701
05/22/16 04:04 PM
05/22/16 04:04 PM
Joined: Mar 2001
Posts: 16,070
USA
R
R. Belmont Online content
Very Senior Member
R. Belmont  Online Content
Very Senior Member
R
Joined: Mar 2001
Posts: 16,070
USA
So is this work in trunk at SIMH, or what? I don't obviously see any WE32k or anything in their default github repo.

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105702
05/22/16 04:11 PM
05/22/16 04:11 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
In fork at https://github.com/sethm/simh, 5620 bits will soon land into https://github.com/shattered/simh

EDIT: pushed newwip branch. keyboard is missing shift and control keys -- going to replace that with serial_terminal code. F12 is setup and F11 is shift-setup -- triggers self-test. Sample SIMH config:

Code:
att nvram       dmd.nvram
att uart        Connect=telehack.com:23,speed=4800
bo cpu


At higher speed it starts losing chars.

Last edited by shattered; 05/22/16 05:28 PM.
Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105737
05/25/16 10:11 PM
05/25/16 10:11 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
I think most of the breakage (in SIMH itself, WE32K cpu core and 5620 sim itself) is now fixed and 5602 is usable (standalone an d under layers). Still, SIMH has no cpu clock and timing-sensitive apps run erratically. Anyhow:

DMD 5620: jim infested by crabs

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105781
05/29/16 03:22 PM
05/29/16 03:22 PM
Joined: Jan 2011
Posts: 179
A
Al Kossow Offline
Senior Member
Al Kossow  Offline
Senior Member
A
Joined: Jan 2011
Posts: 179
Shattered, take a look at the thread just started by Seth on cctlk, in particular the one from Josh

http://yahozna.dyndns.org/scratch/blit/software/

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105798
05/30/16 08:34 PM
05/30/16 08:34 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
aha, wget -r'ing that as well (I've mirrored other stuff from that site before).

Re: AT&T Blit, DMD 5620 et cetera [Re: shattered] #105814
05/31/16 06:32 PM
05/31/16 06:32 PM
Joined: May 2012
Posts: 490
S
shattered Offline OP
Senior Member
shattered  Offline OP
Senior Member
S
Joined: May 2012
Posts: 490
Stupid 5620 tricks while real software isn't running:


DMD 5620: Open Cubic Player

Page 2 of 3 1 2 3

Who's Online Now
3 registered members (Reznor007, Breiztiger, 1 invisible), 128 guests, and 3 spiders.
Key: Admin, Global Mod, Mod
Shout Box
Forum Statistics
Forums9
Topics8,606
Posts112,515
Members4,827
Most Online296
Dec 5th, 2018
Powered by UBB.threads™ PHP Forum Software 7.6.1.1
(Release build 20180111)
Page Time: 0.027s Queries: 15 (0.010s) Memory: 5.7320 MB (Peak: 5.9560 MB) Zlib enabled. Server Time: 2018-12-15 13:23:28 UTC