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TashTwenty: Single-Chip DCD (Hard Disk 20) Interface

tashtari

PIC Whisperer
Would someone mind outlining the formatting procedure for me? It's been awhile and I'm having trouble finding all the info. I know MasterBootRecord for the primary format, but in particular I'm interested in allocating partitions.
Documentation on the subject is here: https://github.com/lampmerchant/tashtwenty#mmc-card-format

Basically, if you're not worried about custom icons, formatting your card with an MBR partition table with only primary partitions of type AF (Mac HFS) should work a treat. On a Plus or 512k, there can be four, but on other machines it won't recognize more than two - this is a limitation of the Mac ROM, not of the firmware.
 

Iesca

Well-known member
Do you have recommendations for transferring stuff off of the card once it's been partitioned and used? Recent versions of macOS can't even mount HFS, but even if I use a system that can, it only shows one of the partitions.
 

tashtari

PIC Whisperer
Hmm. Such systems may not support SD cards having more partitions than one... but I'm just guessing, I myself know little of Macs that don't have 68k processors. D: Anyone else want to chime in on this?
 

Tarantulas

Well-known member
Documentation on the subject is here: https://github.com/lampmerchant/tashtwenty#mmc-card-format

Basically, if you're not worried about custom icons, formatting your card with an MBR partition table with only primary partitions of type AF (Mac HFS) should work a treat. On a Plus or 512k, there can be four, but on other machines it won't recognize more than two - this is a limitation of the Mac ROM, not of the firmware.

What is the best way to format the SD? Would using a real DOS machine be the preferred way? Or am I confused about how you actually go about this?

Sorry, I just saw the post about the python script.
 

WillJac

Well-known member
Boards arrived right as I was heading out of town, so I finally was able to get one assembled today. Still need to get the MCUs programmed and do some testing... but it's otherwise complete! I'll have GitHub links posted here when testing is complete. The SD card slot is a bit of a tight fit when inserting/removing the card; the Rodime is kinda in the way and makes it a little cumbersome to swap SD cards; if you're fine just swapping out the microSD card, it's no worry.

View attachment 48991
This is a great amazing project and wanted to check on the status and availability as I do not see it on your GitHub yet. I am also building many of your Lisa boards for my Lisa rebuild as I have 2 of them to fix. PSU boards (new version) on the way to me. CPU board I have also but not sure I need to rebuild mine yet. Anyway, Thanks for the great work you do as it is very beneficial to me and many others in the community. Let me know when the Mega is available on your GitHub.
 

Jockelill

Well-known member
Oh, wünderbar! Can you elaborate on the difference between the "top/bottom" and "tashtwenty_case_top/bottom" STLs?
Yeah, I could have been a bit clearer :). There are actually two versions of the case, one with holes and one without. Each case consists of two parts, a top and a bottom, they are screwed together with countersink 2.5mm 12mm long wood screw.

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I have actually modelled the DB19-connector also and succesfully printed that. Same method can also be used to recreate the unobtainable female connector, working on that as well :)

For convinience I've added the two cases in separate zip-files also to this post.
 

Attachments

  • TashTwenty_case_with_holes.zip
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  • TashTwenty_case_without_holes.zip
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olePigeon

Well-known member
A2Heaven sells DB19 female solder cup plugs for $6 each (minimum 2, so $12.) He also has DB19 cable shrouds. Unfortunately his DB19 to IDC20 cable is out of stock (and unlikely to be restocked.) That would have been perfect for rerouting an internal floppy port externally. I guess I can crimp my own, but his cable was pre-crimped on the DB19 side. If DB19 female plugs are hen's teeth, then crimpable DB19 female plugs is unicorn poop.
 

Phipli

Well-known member
A2Heaven sells DB19 female solder cup plugs for $6 each (minimum 2, so $12.) He also has DB19 cable shrouds. Unfortunately his DB19 to IDC20 cable is out of stock (and unlikely to be restocked.) That would have been perfect for rerouting an internal floppy port externally. I guess I can crimp my own, but his cable was pre-crimped on the DB19 side. If DB19 female plugs are hen's teeth, then crimpable DB19 female plugs is unicorn poop.
If once a week for a few years a different one of us sends an enquiry to the Chinese firm that makes all the blue crimp dsub connectors, asking about DB19 connectors, perhaps they'll think there is a huge market they're missing out on?
 

Iesca

Well-known member
The holes are for if you've added an activity LED, I assume? (Love the reinforced grips for the Dsub connector!)
 

Jockelill

Well-known member
The holes are for if you've added an activity LED, I assume? (Love the reinforced grips for the Dsub connector!)
Actually they are just for through screws so you can fix it to the plus, i stole those screws of a DB9 I had in the shop. But, yeah, can add a hole for activity also :).
 

Iesca

Well-known member
Actually they are just for through screws so you can fix it to the plus, i stole those screws of a DB9 I had in the shop. But, yeah, can add a hole for activity also :).
Oh! Clever. :) Any idea where to get those sort of screw posts?
 

Jockelill

Well-known member
TLDR:
There is a new more compact case.


The longer story:

When trying to connect the TashTwenty to one of our other Macintosh Plus (an upgraded 128k) I realized that it would collide with the mouse connector for this early generation mouse.

IMG_5651.jpg
So why was the case so wide? Well, I wanted to be able to screw it into the Macintosh, (that was why there was a version with holes through it), and then I just filled those holes in the CAD and kept it wide since it would anyway fit on my other Macintosh Plus with another connector for the mouse (a.k.a "lazy engineering").

But the problem urged me to come up with a solution, so I made some design changes, ditched the screws and it is now not wider than the DB19-connector itself.
IMG_5654.jpg

Out with the old:
IMG_5652.jpg

In with the new:
IMG_5653.jpg

Yeah, I need to clean that connector from dust also :).
 

Attachments

  • TashTwenty_case_compact.zip
    298 KB · Views: 12
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