Sorry to send this to the entire list but I have been unable to contact
Roger by private email. Apparently, my messages get put in his junk
mail file.
Roger: Please call me at 603-472-2389 to discuss the HHC Basic ROMs.
> Me? I got a CAR FULL of DEC software and documentation!
Send an advice the day that you want get rid of all the stuff, please. Get
DEC items like PDP8's in Europe is more difficult day by day.
Regards
Sergio
>I have an extensive inventory and can source the parts and get this poor, battered
>board back to its old self again. However, looking through the doco I noticed that
>the 8800B requires a display/control and interface boards. A question for those of
>you that own a MITS8800 - does it need those boards for a turnkey system? Can I
>plug the CPU board into the backplane and run it without the d/c and i/f cards,
>assuming I set up the ROM and RAM cards for the system? If not, (since I do not
>have the d/c and i/f cards) I'll have to try and build them from the cct diagrams
>I have obtained. This is do-able (but a lot of work) if I can get my hands on some
>blank S100 w/wrap boards, but I noticed there's a 1702 EPROM chip and I'd need to
>get the memory map for this chip to burn my own.
The two main things the front panel provides to the running systems (not counting
debug functions) are:
- The front panel generates the MEMORY WRITE signal to the bus. If you do not
have a front panel, then you will need to generate this signal with a little
"glue logic".
- The front panel also generates a POWER ON JUMP, allowing the processor to
launch at an address other than 0000 - this is necessary if you want to run
an operating system such as CP/M which requires RAM at 0000.
If you don't need RAM at 0000, then just put your bootstrap ROM at 0000 and
you should be good to go.
If you do need RAM at 0000, then you will need to add a bit of circutry to
allow your rom to "MOVE". One simple way, assuming you want to put your ROM
at an address >= 8000 is to upon RESET, double-map your ROM to it's correct
address (>= 8000) AND at 0000. While doing this, you need to pull the
phantom signal to disable any RAM at 0000 - Begin your bootstrap code with
a JMP to it's correct address (+3) ... As soon as you see an instruction
fetch with the high bit set, release the double-map at 0000 and phantom,
and your system will be operating normally from the ROM at the higher
address.
Regards,
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html
Hi,
Great, thanks for the info.
I'm sourcing a few S100 protoboards, so I'll be able to wirewrap a board with all the relevant RAM, ROM and I/O. I'll probably use later generation chips such as 62256 for RAM and 6264 for ROM. I can then put in the 8251 and 8255 for serial and parallel ports, respectively. Is that heresy in regards to these old boards?
It's not an issue to me starting ROM at 0000h. I've written a few 8080 debug/monitors for my old Multibus stuff so I can always use one of these - or mod it accordingly.
I've only got a 6-slot motherboard and a Northstar ZCB processor board, S100 ROM board and some Dynabyte RAM boards and I was going to use the motherboard and original S100 boards with this system. This means the 8800CPU board will be in a small 2-slot system - the CPU board and the RAM/ROM/IO board I'm going to make.
I'll check the MWRITE signals and see what I can do, or if you have the info then that's even better.
Just one more thing.... I suppose it's possible to use the 8800CPU bd without the power regulation components if I ensure the correct voltages go through the correct pins on the bus. I can then use an old spare PC power supply, instead of creating a new supply. Naturally, this would entail that no other S100 board can be used due to their on-board regulators. This isn't an issue if I build my own S100 boards, without regulation, for this system.
Again, thanks for your help. This is my first foray into S100 stuff, and makes a nice change from Multibus.
rgds
river
>
>Subject: PDP 11/23+ progress
> From: "Jim Beacon" <jim at g1jbg.co.uk>
> Date: Mon, 13 Jun 2005 19:33:14 +0100
> To: "Classic computer list" <cctalk at classiccmp.org>
>
>I finally managed to get my OEM 11/23+ to boot from the RL02 today, the
>solution to the OEM boot ROM problem was to set the RLV12 addressing mode to
>18 bit, rather than 22bit. I assume that this is a feature of the OEM boot
>program :-)
>
>I'm now getting garbage on the terminal, but have yet to figure out which
>setting I've got wrong!
>
>Jim.
>
>Please see our website the " Vintage Communication Pages" at WWW.G1JBG.CO.UK
Likely baud rate. Try 4800n1.
Allison
>From: "river" <river at zip.com.au>
>
>Hi,
>
>Thanks for your replies. I found the relevant information.
>
>I have an extensive inventory and can source the parts and get this poor,
battered board back to its old self again. However, looking through the doco I
noticed that the 8800B requires a display/control and interface boards. A
question for those of you that own a MITS8800 - does it need those boards for a
turnkey system? Can I plug the CPU board into the backplane and run it without
the d/c and i/f cards, assuming I set up the ROM and RAM cards for the system?
If not, (since I do not have the d/c and i/f cards) I'll have to try and build
them from the cct diagrams I have obtained. This is do-able (but a lot of work)
if I can get my hands on some blank S100 w/wrap boards, but I noticed there's a
1702 EPROM chip and I'd need to get the memory map for this chip to burn my own.
>
>Failing that, and it's all too hard and bothersome for me, is there anyone that
would need a repaired 8800 CPU card for trade or anything similar?
>
>rgds
>river
>
Hi
It should work on a turnkey. Almost everything goes
through the S100 bus. Only the direct connect of the
data bus goes directly between the panel and the CPU board.
I don't think that is needed. You will have to have code
residing at address 0000. This is not common. Most
expected a working front panel that could load a boot
address.
Some ROM boards have a way to be at 0000 after reset
and then switch to someplace else once things are booted.
Don't give up on it. When there is a will, there will
be a way.
Dwight
>
>Subject: Re: Wild-hair floppy drive question
> From: "Randy McLaughlin" <cctalk at randy482.com>
> Date: Mon, 13 Jun 2005 18:39:14 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>From: "Doc Shipley" <doc at mdrconsult.com>
>Sent: Monday, June 13, 2005 6:33 PM
>
>
>> Randy McLaughlin wrote:
><snip>
>>> To make the Teac 1.2mb drive act like a QD drive there are two options:
>>>
>>> Jumper I on, LG off, low on pin 2 of the 34 pin connector or Jumper I on,
>>> LG on, high on pin 2 of the 34 pin connector.
>>
>> Thanks. I think it was the flip-flop on pin 2 that was hammering me.
>>
>> I'm suddenly in the middle of a Tivoli TSM migration, but when things
>> cool off abit I'll try this.
>>
>>
>> Doc
>
>You would think they would have included a jumper to select the speed and
>ignore pin 2.
>
>The best thing would be to cut the trace and ground it so the signal doesn't
>go back to the controller. As a matter of fact cutting pin 34 often helps.
>
Actually on some varients the jumper does exactly that, with a
pair to select if the "input" are high or low another only has a
single jumper to select low with a pull up. I have five
different FD55GFx flavors with boards that are markedly
differnt. Most annoying. But they have proven to be reliable.
Allison
Hi,
Thanks for your replies. I found the relevant information.
I have an extensive inventory and can source the parts and get this poor, battered board back to its old self again. However, looking through the doco I noticed that the 8800B requires a display/control and interface boards. A question for those of you that own a MITS8800 - does it need those boards for a turnkey system? Can I plug the CPU board into the backplane and run it without the d/c and i/f cards, assuming I set up the ROM and RAM cards for the system? If not, (since I do not have the d/c and i/f cards) I'll have to try and build them from the cct diagrams I have obtained. This is do-able (but a lot of work) if I can get my hands on some blank S100 w/wrap boards, but I noticed there's a 1702 EPROM chip and I'd need to get the memory map for this chip to burn my own.
Failing that, and it's all too hard and bothersome for me, is there anyone that would need a repaired 8800 CPU card for trade or anything similar?
rgds
river
>
>Subject: Re: Wild-hair floppy drive question
> From: Doc Shipley <doc at mdrconsult.com>
> Date: Sat, 11 Jun 2005 20:01:12 -0500
> To: General at mdrconsult.com, "Discussion at mdrconsult.com":On-Topic and Off-Topic
> Posts <cctalk at classiccmp.org>
>
>Eric Smith wrote:
>
>> Doc asks:
>>
>>> Would a DSHD floppy drive with a DSHD disk in it
>>
>>
>> You mean a 96 TPI high-density 5.25" disk and drive (e.g., IBM 1.2M format
>> that was introduced with the PC/AT)?
>
> Sorry, no, I meant a 3.5" floppy drive. As soon as Allison replied I
>realized the question was ambiguous.
>
> I've found something intersting about the Compaq m/b that hosts my
>1.2MB 5.25" disk drive, though.
>
> That board auto-detects all its hardware on every boot. If I boot
>with a DSQD disk in that drive, the BIOS auto-updates the settings to
>'3.5" 1.44MB Drive".
>
> Which is what prompted my question in the first place.
Ah, so you wish to use a 3.5" floppy for an Altos that has a 5.25 DSQD?
If that is the question the answer is yes. (use one hole media aka 720k).
If not a TEAC FD55GFV will work as a DSQD 5.25".
Allison
It was with interest that I saw a posting that said no 6 wide Qbus
cards existed. I have a couple I think. I have two of PCB 136 Qbus sys
boards.
http://members.aol.com/innfosale/ebay/136qbus1.jpg
I think they are like a console card as they have eproms, LEDs,
switches to set, Tst/Nor, Hit/Run and restart switches.
Maybe came out of a qbus card tester?
I have a SDLC card, PCB127 that I will get pics up shortly that is 6
wide but not marked qbus but is a similar board number sequence. This
board has a 2652 CPU.
http://members.aol.com/innfosale/ebay/127qbus1.jpg
So are they qbus cards?
--
Paxton Hoag
Astoria, OR
USA
