29 Nov
2014
29 Nov
'14
10:55 a.m.
Folks,
For some reason I got it in my head that writing an AT&T 3B2 emulator
might be a good idea. That idea has pretty much been derailed by lack
of documentation.
I have been unable to find any detailed technical description of any
3B2 systems. Visual inspection of a 3B2 300 main board reveals the
following major components:
- WE32100 CPU
- WE32101 MMU
- 4 x D2764A EPROM
- TMS2797NL floppy disk controller
- PD7261A hard disk controller
- SCN2681A dual UART
- AM9517A Multimode DMA Controller
How these are addressed is anybody's guess.
To even dream of doing an emulator, I at least need to know the system
memory map -- what physical addresses these devices map to. Without
that it's pretty pointless to get started.
If anyone has access to this kind of information, please drop me a
line. Otherwise, I'll just put this one on the far-back burner!
-Seth
29 Nov
29 Nov
2:19 p.m.
Don't give up Seth this is a worthy cause
http://www.wickensonline.co.uk
http://declegacy.org.uk
http://retrochallenge.net
https://twitter.com/#!/%40urbancamo
On 29 Nov 2014, at 18:55, Seth Morabito <lists at
loomcom.com> wrote:
Folks,
For some reason I got it in my head that writing an AT&T 3B2 emulator
might be a good idea. That idea has pretty much been derailed by lack
of documentation.
I have been unable to find any detailed technical description of any
3B2 systems. Visual inspection of a 3B2 300 main board reveals the
following major components:
- WE32100 CPU
- WE32101 MMU
- 4 x D2764A EPROM
- TMS2797NL floppy disk controller
- PD7261A hard disk controller
- SCN2681A dual UART
- AM9517A Multimode DMA Controller
How these are addressed is anybody's guess.
To even dream of doing an emulator, I at least need to know the system
memory map -- what physical addresses these devices map to. Without
that it's pretty pointless to get started.
If anyone has access to this kind of information, please drop me a
line. Otherwise, I'll just put this one on the far-back burner!
-Seth
3:15 p.m.
* On Sat, Nov 29, 2014 at 02:26:39PM -0800, Al Kossow <aek at bitsavers.org> wrote:
Do you have access to the AT&T SVR4 sources? 3B2 was the porting
base machine.
I do, and that's an excellent idea.
Digging through the sources turned up the vuifile (which, as I
understand it, is a linking map for the kernel) and the section
attached below may be the information I need. It looks like the system
board IO space starts at 0x40000. The MMU's registers described in the
WE 32101 datasheet look like the correspond to the symbols mmusdc1,
mmusdc2, mmupdc1r, mmupdc2r, etc... up to mmuvar.
I'm sure much more will be revealed as I read through the sources to
see how the rest of the symbols are used.
-Seth
------------------------->8 snip 8<---------------------------------
MEMORY {
KP_boot: origin = 0x2004000, length = 0x80000
KV_gate: origin = 0, length = 0x800
KV_demot: origin = 0x20000, length = 0x20000
KV_sbdint: origin = 0x40000, length = 0x20000
KV_text: origin = 0x40000000, length = 0x160000
KV_data: origin = 0x40160000, length = 0x20000
KV_bss: origin = 0x40180000, length = 0x160000
KV_sysseg: origin = 0x402e0000, length = 0x200000
KV_windows: origin = 0x404e0000, length = 0x40000
UV_ublock: origin = 0xc0000000, length = 0x20000
UV_stack: origin = 0xc0020000, length = 0xe0000
}
[...]
kv_sbdint (NOLOAD):
{
unxsbdst = . ;
mmusdc1 = . ;
mmusdc2 = . + 0x100;
mmupdc1r = . + 0x200;
mmupdc2r = . + 0x300;
mmupdc1l = . + 0x400;
mmupdc2l = . + 0x500;
mmusrama = . + 0x600;
mmusramb = . + 0x700;
mmufltcr = . + 0x800;
mmufltar = . + 0x900;
mmucr = . + 0xa00;
mmuvar = . + 0xb00;
sbdpit = . + 0x2000;
clrclkint = . + 0x2013;
sbdnvram = . + 0x3000;
sbdrcsr = . + 0x4000;
sbdwcsr = . + 0x4000;
dmaid = . + 0x5000;
dmaiuA = . + 0x6000;
dmaiuB = . + 0x7000;
dmac = . + 0x8000;
duart = . + 0x9000;
idisk = . + 0xa000;
ifloppy = . + 0xd000;
dmaif = . + 0xe000;
} > KV_sbdint
------------------------->8 snip 8<---------------------------------
10:44 p.m.
On Sat, Nov 29, 2014 at 4:19 PM, Mark Wickens <mark at wickensonline.co.uk> wrote:
Don't give up Seth this is a worthy cause
Let me second that. The 3B2 is a crucial machine in UNIX history -
and just really cool, too. I doubt I'd be much help with an emulator
but best of luck with the project.
(Now who's going to write the BLIT terminal emulator to go with it? :)
-j
30 Nov
30 Nov
1:30 a.m.
On Sat, Nov 29, 2014 at 11:44 PM, Jason T <silent700 at gmail.com> wrote:
(Now who's going to write the BLIT terminal
emulator to go with it? :)
If Seth writes a 32100 CPU simulator, simulating a 5620 should be
relatively easy, as the rest of the 5620 hardware is fairly simple
(much simpler than a 3B2).
29 Nov
29 Nov
3:15 p.m.
Well, I have a complete set of the red manuals for it (including
some wierd things like about how to build its boot prom).
I have no need for this stuff.
Where are you located?
mcl
3674
days inactive
3675
days old
6 comments
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participants (6)
-
aek＠bitsavers.org -
linimon＠lonesome.com -
lists＠loomcom.com -
mark＠wickensonline.co.uk -
silent700＠gmail.com -
spacewar＠gmail.com