Building TJBoldt's ProDOS ROM Drive for Apple ][

[skate323k137]

I've been on an apple II kick lately, and even though I have plenty of storage for my machines, I couldn't stop myself from trying out this project:

GitHub - tjboldt/ProDOS-ROM-Drive: A bootable 1 MB solid state disk for Apple ][ computers

A bootable 1 MB solid state disk for Apple ][ computers - tjboldt/ProDOS-ROM-Drive

github.com

The card is an Apple II slot card consisting just of simple DIP chips and 0.1uf capacitors. The storage is an 8mbit / 1MB 27c801 EPROM. The git repo has 2 example ROMs, one loaded out with BASIC and some games, and one empty with just the drive firmware on it, and the rest of the space free. I have had some success copying files into this image in an emulator, burning the EPROM, and then putting it onto the card. Obviously once you program it to the physical ROM, it's read only.

There were some for sale on eBay as this is an open source design, but none of the new revision, and none in the US, making a $25 purchase more like a $50 purchase. The budget was kind of the appealing part; I could see this being really useful for testing 'untested' machines, as for $10-$20 worth of parts and some soldering, you have a bootable solid state apple II drive that requires no disk controller or drives to be present. Or if you really use a certain app all the time, and don't want a microdrive turbo, putting that app to ROM and booting to that slot near instantly would be neat I suppose too.

I built this one with a ZIF so I can test different roms, which is fine for slot 7 room wise, but for actual installation / long term use if I actually needed it, I would just use a normal socket. The card itself is quite compact, card pictured with a microdrive turbo for scale.

 

[skate323k137]

I made an alternate ROM image for this card which contains some utilities. I will likely update it further, but full information is here:

Alternate ROM image for TJBoldt ProDOS Rom Drive (ProDOS 2.4.2 + utils) | Applefritter

www.applefritter.com

DOWNLOAD Latest version: https://photosuckit.com/ProDOS242_Beta5.po
Burn to 27c801 EPROM.

Aimed at II+ and IIe, it contains:
ProDos 2.4.2 / Bitsy Bye
Copy II Plus
ADTPro
Joystick calibration tester
video test
color test
iie test
games (A few, tetris and some others, still have 1/2 the ROM space left but was focusing on utilities).
license

Boot screen of Bitsy Bye (Loads very fast):

I appreciate Feedback if you try this ROM image, especially if you have in mind other utilities which you know can be run from a ProDOS volume.

 

[skate323k137]

Paging IIgs Owners:

I have booted GSOS from this ROM Drive successfully (with some limitations), including the SCSI driver which gives the ability to access a BlueSCSI if you have a SCSI Card. Why? Well, that's why I'm making this post I suppose.

Would anyone here have any reason to use a Read Only GSOS boot drive? I have gotten it kind of working, but it's definitely at a point of "Is there any reason to pursue finishing this correctly and actually spend time on bugs."

One major thing stopping me is that a solution like the MicroDrive Turbo is cheaper than a SCSI card, very fast, and of course writeable. Also, as far as I know, SCSI can really only be used as storage and not a boot device for GSOS, since the boot disk itself has to contain the SCSI Drivers, whether that boot disk is a floppy, MicroDrive, etc.

So aside from people with just floppy drives, unless you happen to be sitting on a SCSI card you're not using, I question the real value of this disk image should I take the time to complete it. I do suppose though if you just had a FloppyEMU, it may add some value booting from a cheap fast internal drive and accessing your floppies on the desktop. Thoughts welcome of course.

 

[skate323k137]

IIGS GSOS 6.0.1 w/mass storage support ROM image for TJBoldt ROM drive:

https://photosuckit.com/IIGS_Mass_nofinderinfo_1MB_withfirmware.po

More info:

GSOS R/O ROM image for TJBoldt ProDOS Rom Drive (GSOS 6.0.1) | Applefritter

www.applefritter.com

 

[retr01]

Hi @skate323k137!

I see you have been hollering for the Apple IIGS owners. I still own one and a half. One is entirely the other is just a case and a power supply.

That is neat! Can you post a video so we can see the speed difference? I understand that putting GSOS on the ROM card means it runs nicely without the slowdowns associated with SD, FloppyEMU, and even the Apple 3.5" disk drive.

 

[skate323k137]

Hi @skate323k137!

I see you have been hollering for the Apple IIGS owners. I still own one and a half. One is entirely the other is just a case and a power supply.

That is neat! Can you post a video so we can see the speed difference? I understand that putting GSOS on the ROM card means it runs nicely without the slowdowns associated with SD, FloppyEMU, and even the Apple 3.5" disk drive.

Very nice, thank you for the reply. The one that is a case and power supply sounds like a perfect candidate for this perhaps, if a logic board falls from the sky (fingers crossed for you).

For a video, would a comparison of the same GSOS image on a FloppyEMU 800k mode compared with this be a good comparison for you?

 

[retr01]

Very nice, thank you for the reply. The one that is a case and power supply sounds like a perfect candidate for this perhaps, if a logic board falls from the sky (fingers crossed for you).

*looks up to the sky and holds out my hands to see if any will fall* Oh, maybe not yet? Ha.

For a video, would a comparison of the same GSOS image on a FloppyEMU 800k mode compared with this be a good comparison for you?

Sure! Nowadays, the FloppyEMU is in demand among Apple II owners. That will be a good comparison.