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PDP11GY
July 29th, 2009, 05:28 AM
Hello @ ALL and regards from Germany,
I'm continuous involved restoring Vintage ( DEC ) Computers and the primary problem is related to mechanical issues with HARD-DISK devices, eg. RL02/RX02. You may find an overview by my projects: http://www.youtube.com/user/PDP11GY
Solution ?..? : I am planing to simulate a RL02 via PIC evironment and flash SD card.
This would bring me in the great situation to be able to run all DEC operating systems just
from a simple SD flash , eg OS-8, RT-11, RSX-11, VAX-VMS.
Does anyone have any concerns , infos or was anyone already involved in such a project ?
Many thanks in advance and regards,
Reinhard

cosam
July 29th, 2009, 05:58 AM
Do you want to emulate just the RL02 drive or the controller as well? The drive alone would be useful, but it'd be great to just plug in a Qbus/Unibus module and go.

What I'd really like to see is an MSCP to flash card adapter. Last time I looked there were a couple of MSCP to ATA/IDE projects going (so it'd only take an adapter to be able to use a CF card) but I don't remember any of them actually getting finished.

pontus
July 29th, 2009, 10:27 AM
Spare time gizmos has a TU58 simulator in hardware, and there are some in software.

This project looks neat, but I'm not sure about its status:

http://www.mscpscsi.com/

PDP11GY
July 30th, 2009, 03:59 AM
Hello. That's correct, I will try to simulate the RL02 drive only. I found out 3 possibilities:
1) Design a virtual Memory used as "RAM disk" , direct connected to the system-bus.
Advantage: relatively easy to design, Most system have a RAM disk device driver already available. May run very fast Disadvantage: Needs a extra design for every System-Bus. e.g. Unibus, QBus, CTI Bus ....and so on.
2) Using a standard parallel Interface and connect it to a PIC processor environment maybe using also a parallel / USB converter .Advantage: This would be a generel purpose solution because every system should have a parallel interface available. Disadvantage: a device driver has to be (re)written for every sytem.
3) Simulate a storage device ( RL02 )via PIC environment. In the DEC world for example, simulate a Rx02 or Rl02 via connecting the I/O cable to a PIC environment instead of the old storage equipment. Advantage: It would be very simple of use because every operating system has a RL02 Devicer already included. Disadvantage: Engineering this PIC-board will be go complicated ?

This analysis induced me to try to use solution nr 3).
MSCP device simulation sounds very(!) interesting to me ! ... but I have no timing und protocoll engineering specification available .

PDP11GY
July 30th, 2009, 04:06 AM
Very interesting Info, thanks

Lou - N2MIY
July 30th, 2009, 02:43 PM
Gents,

Here is another interesting project that Crawford and I have been considering: http://www.chd.dyndns.org/qbus_ide/

It's a homemade PIO Qbus IDE disk controller. It's not MSCP.

Since I don't have the $$$$ for a commercial qbus SCSI controller, this looks really appealing, especially since I like RT-11.

Lou

pontus
July 30th, 2009, 10:05 PM
Gents,

Here is another interesting project that Crawford and I have been considering: http://www.chd.dyndns.org/qbus_ide/

It's a homemade PIO Qbus IDE disk controller. It's not MSCP.

Since I don't have the $$$$ for a commercial qbus SCSI controller, this looks really appealing, especially since I like RT-11.

Lou

If you hurry, this is a reasonable price

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230362413145

cosam
July 30th, 2009, 11:52 PM
If you hurry, this is a reasonable price

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230362413145
Hmm... the field guide has the DILOG SQ703A listed as a SCSI TMSCP controller. If that's right, you wouldn't be able to hang any disks on it, only tape drives. Too bad - I would've snapped one up for sure.

pontus
July 31st, 2009, 12:02 AM
Hmm... the field guide has the DILOG SQ703A listed as a SCSI TMSCP controller. If that's right, you wouldn't be able to hang any disks on it, only tape drives. Too bad - I would've snapped one up for sure.

Ah, good that I didn't go for one myself :)