Priam DataTower Replica

[Al Kossow]

Has anyone ever thought about a Priam Datatower interface / emulator board?
The drive has a driver in 7/7 and people are going to want a large drive for the full 7/7 code build.

[AlexTheCat123]

That sounds like a great idea! Do we have enough info about the Datatower and its communications protocol in order to do something like this? I've looked around for information a couple times in the past, but I don't remember finding anything other than blurry photos of its components; definitely no schematics or descriptions of the protocol.

[Al Kossow]

The SMART-T controller protocol is under priam on bitsavers

sigma7's thread on the intf
https://lisalist2.com/index.php/topic,296.0.html

[compu_85]

And now I'll be thinking about an ideTower over night

-J

[stepleton]

With the source code for the operating system, a minimal-hardware alternative would be to modify the Lisa OS to handle bigger hard disks. ProFile emulators can go bigger than just 5 or 10 MiB --- Cameo/Aphid for example can do hundreds of megabytes.

[sigma7]

ProFile emulators can go bigger than just 5 or 10 MiB

The X/ProFile has been tested with STARs up to 2 GB ($3F FF F0 blocks) -- the OS logical disk limit during the System 7 / MW+II era.

It also has settings for 4GB and 8GB ($7F FF F0 and $FF FF F0 blocks), but IIRC these are untested due to there being no environment/driver to test them against.

[AlexTheCat123]

With the source code for the operating system, a minimal-hardware alternative would be to modify the Lisa OS to handle bigger hard disks. ProFile emulators can go bigger than just 5 or 10 MiB --- Cameo/Aphid for example can do hundreds of megabytes.

That's a good point! It looks like the Cameo/Aphid, X/ProFile, ArduinoFile, and IDEFile all support volumes larger than 10MB, so we might want to give that a try before going to the trouble to emulate the DataTower.

[rayarachelian]

With the source code for the operating system, a minimal-hardware alternative would be to modify the Lisa OS to handle bigger hard disks. ProFile emulators can go bigger than just 5 or 10 MiB --- Cameo/Aphid for example can do hundreds of megabytes.

That's a good point! It looks like the Cameo/Aphid, X/ProFile, ArduinoFile, and IDEFile all support volumes larger than 10MB, so we might want to give that a try before going to the trouble to emulate the DataTower.

Keep in mind, there may be hard limits not just in the ProFile driver, but also in the Lisa File System itself that will prevent very large volumes.

I don't remember the size off the top of my head, but barely remember articles about the DataTower saying that it didn't put up one large volume, but rather something like 4. Since the size is 80MB, that's likely the unformatted size, so more likely 64MB is useable, and divided by 4 that might set the limit to 16MB/vol? I'm just guessing here, I don't have a DataTower, so could be totally wrong.

This might have been for an earlier version of LOS as well, so, no idea really. We'll know when it's implemented, I suppose.

[sigma7]

I don't remember the size off the top of my head, but barely remember articles about the DataTower saying that it didn't put up one large volume, but rather something like 4.

IIRC, it can appear as one volume (perhaps can be configured otherwise). I believe there is a BLU dump of the DataTower formatted with LOS floating about that is in this configuration.

2022-12-11: BTW... this thread split from Alex's I/O board replica as a new topic

[Al Kossow]

Just wanted to point out that you need the space for a workshop 3.0 instance, not 7/7

[compu_85]

The Signal newsletter's reviews of the Data Tower make it sound like it presents to the OS as one big volume, which can be picked from the Startup From menu:

http://www.macmothership.com/lisacontent/signal/Signal16_September1984.html
We quickly installed a 3.0 Office System on the new disk, and we were off and running. Now Attributes shows 142,420 blocks for our disk device.

http://www.macmothership.com/lisacontent/signal/Signal18_November1984.html
7/7 supports an enormous number of files, so that the entire disk can easily be put to use. At one point in our testing, we loaded the DataTower with 4,735 documents and folders occupying almost 70 megabtyes of disk.
Unlike Mac's Finder, which begins to thrash when even fewer than 100 files have accumulated, 7/7 (and even the 3.0 Workshop!) took the load in stride, performing opens and saves as quickly as when the disk is empty.

Having the parallel track (no pun intended!!) of modifying the LOS disk driver to support an IDEFile-16 or IDEFile-32 would be sweet!

-J