• Please review our updated Terms and Rules here

The Frob: It needs some rev-eng love.

btb said:
Any idea what that logo is supposed to represent? Does this look like a good enough facsimile to put on the board?

View attachment 1299225
Click to expand...
It was just kind of a gnome made from the letter "f", with a face in the negative space. Many liked it, but a few told us they thought it was obscene. In those days the word "frob" was technical slang that started as a verb. Then, "to frob" was to twiddle a knob on some electronic device without any specific reason. Then, a random control knob or slider might be called a "frob." I can't remember if I or Frank originally suggested the name, but we both liked it.
 
  • Like
Reactions: btb
Not only has the Frob #Atari2600 #Gamedev System for #Apple2 been #reveng, Golden Child from #MAMEDEV has emulated it in MAME!
 
  • Like
Reactions: btb
tschak909 said:
Funny enough, I wonder if anyone has a Frob Burner? It was a companion card that had a card edge that the cartridges could plug into, and it would burn them (after inserting a suitable 2732 eprom)
Click to expand...
I imagine you have seen this, but if not: https://www.atarimania.com/game-atari-2600-vcs-frob-26_29983.html
There's the manual for the burner, with source listings. No photos of it though. There are photos of the newer, keyed cartridge adapter that is needed for it.
There's also a picture of the 5200 cartridge adapter, and the brochure. Also shows the manuals for the 5200 version, but unfortunately no scans.
 
@Ken Clements , do you know anything about the origin of those PPC360AN chips? A special run of chips to fill a shortage or was something else going on?
 
  • Like
Reactions: cjs
btb said:
@Ken Clements , do you know anything about the origin of those PPC360AN chips? A special run of chips to fill a shortage or was something else going on?
Click to expand...
Hi btb. Thom asked me that in email, so here is the best I can tell you. I don't exactly remember, but suspect that those are some ordinary logic IC that has been special labeled. It is why I am looking through all my boxes of junk to find the original wire-wrap prototype, because it will have the ordinary parts on it, and I can just look. FrobCo was a division of Pacific Polytechnical Corp. (we were doing stand-up video arcade games) and that is the PPC part of the PPC360AN label. I also don't remember who decided we needed to special label the parts. At the time we did not have access to FPGAs or any programmable parts more advanced than ROMs, and I know we were not programming any of our own parts, or buying custom chips. That is all I can tell you until I make the find, and I am 73 years old with entire rooms packed with junk prototypes going back 60 years. I am going to have to clear out one room, just to have a place to transfer junk into so I can get into that room full of stuff. Always remember, junk is stuff you throw away, and stuff is junk you save.
 
@btb I have commit up on a branch dev/cjs/25d16/kicad-rename to merge both the KiCad projects (a2board and vcsboard) into a single kicad/ subdir, which I think is a bit more clear from both the ls point of view and helps keep the number of directories down. I don't see any particular issues with this, since I'm sure I've done several different KiCad projects in one directory before, but I just wanted to check with you before merging this.

If you see no problems, you can either rebase this on to main and do a fast-forward "merge", or I'll do it. (It's basically just, git fetch && git rebase main@{u} && git push origin @:main.)
 
Last edited:
Ken Clements said:
Hi btb. Thom asked me that in email, so here is the best I can tell you. I don't exactly remember, but suspect that those are some ordinary logic IC that has been special labeled. It is why I am looking through all my boxes of junk to find the original wire-wrap prototype, because it will have the ordinary parts on it, and I can just look. FrobCo was a division of Pacific Polytechnical Corp. (we were doing stand-up video arcade games) and that is the PPC part of the PPC360AN label. I also don't remember who decided we needed to special label the parts. At the time we did not have access to FPGAs or any programmable parts more advanced than ROMs, and I know we were not programming any of our own parts, or buying custom chips. That is all I can tell you until I make the find, and I am 73 years old with entire rooms packed with junk prototypes going back 60 years. I am going to have to clear out one room, just to have a place to transfer junk into so I can get into that room full of stuff. Always remember, junk is stuff you throw away, and stuff is junk you save.
Click to expand...
@btb was able to figure out that we could use a 74LS367 for those chips (as those are currently made). (If anything I'd guess PPC360 = 74LS360?)

-Thom
 
FWIW, I've pushed up my start on a Theory of Operation. It's only partially complete, and hasn't been well checked. I'm also not sure how useful it really is. It seems as if it would be, because it's darn hard to write, but I still somehow feel as if the operation is pretty obvious from the general idea and the schematics. (This may be influenced by that I've been thinking for a couple of years now about doing a similar "shared SRAM" ROM emulator for other systems, so I already have a general idea of how it works.) Maybe what this really wants is a higher-level of explanation, rather than (or in addition to) the gory details of how all the logic works?
 
cjs said:
FWIW, I've pushed up my start on a Theory of Operation. It's only partially complete, and hasn't been well checked. I'm also not sure how useful it really is. It seems as if it would be, because it's darn hard to write, but I still somehow feel as if the operation is pretty obvious from the general idea and the schematics. (This may be influenced by that I've been thinking for a couple of years now about doing a similar "shared SRAM" ROM emulator for other systems, so I already have a general idea of how it works.) Maybe what this really wants is a higher-level of explanation, rather than (or in addition to) the gory details of how all the logic works?
Click to expand...
FWIW, this document is useful to me. :)
-Thom
 
  • Like
Reactions: cjs
cjs said:
@btb I have commit up on a branch dev/cjs/25d16/kicad-rename to merge both the KiCad projects (a2board and vcsboard) into a single kicad/ subdir, which I think is a bit more clear from both the ls point of view and helps keep the number of directories down. I don't see any particular issues with this, since I'm sure I've done several different KiCad projects in one directory before, but I just wanted to check with you before merging this.

If you see no problems, you can either rebase this on to main and do a fast-forward "merge", or I'll do it. (It's basically just, git fetch && git rebase main@{u} && git push origin @:main.)
Click to expand...

That sounds fine to me. I don't really have my head around the @{} syntax, so I just did a regular "git merge".

Ken Clements said:
Hi btb. Thom asked me that in email, so here is the best I can tell you. I don't exactly remember, but suspect that those are some ordinary logic IC that has been special labeled. It is why I am looking through all my boxes of junk to find the original wire-wrap prototype, because it will have the ordinary parts on it, and I can just look. FrobCo was a division of Pacific Polytechnical Corp. (we were doing stand-up video arcade games) and that is the PPC part of the PPC360AN label. I also don't remember who decided we needed to special label the parts. At the time we did not have access to FPGAs or any programmable parts more advanced than ROMs, and I know we were not programming any of our own parts, or buying custom chips. That is all I can tell you until I make the find, and I am 73 years old with entire rooms packed with junk prototypes going back 60 years. I am going to have to clear out one room, just to have a place to transfer junk into so I can get into that room full of stuff. Always remember, junk is stuff you throw away, and stuff is junk you save.
Click to expand...

That'd be great to see some of those prototypes! I expect it'll just have the regular 74LS chips, yeah.

tschak909 said:
@btb was able to figure out that we could use a 74LS367 for those chips (as those are currently made). (If anything I'd guess PPC360 = 74LS360?)

-Thom
Click to expand...
There was never any such thing as a 74LS360 AFAIK. The substitution here reminds me of how Commodore was making C64s so fast they would run out of some common TTL chips. Since they owned MOS, they just had them made their own equivalent chips with their own part numbers, and used those. The quality was not great so these are some of the most common parts to fail on those machines.

tschak909 said:
How should we handle an initial board run?
-Thom
Click to expand...

I already ordered a sample run of 5 boards, and I think I have enough parts around that I can build up two of them. I'd be happy to send one of those to you or someone else who actually knows how to use it.
 
btb said:
That sounds fine to me. I don't really have my head around the @{} syntax, so I just did a regular "git merge".



That'd be great to see some of those prototypes! I expect it'll just have the regular 74LS chips, yeah.


There was never any such thing as a 74LS360 AFAIK. The substitution here reminds me of how Commodore was making C64s so fast they would run out of some common TTL chips. Since they owned MOS, they just had them made their own equivalent chips with their own part numbers, and used those. The quality was not great so these are some of the most common parts to fail on those machines.



I already ordered a sample run of 5 boards, and I think I have enough parts around that I can build up two of them. I'd be happy to send one of those to you or someone else who actually knows how to use it.
Click to expand...
I can definitely test and make sure the board works as intended, so I would like one of those boards.
 
btb said:
That sounds fine to me. I don't really have my head around the @{} syntax, so I just did a regular "git merge".
Click to expand...
Lol, that leaves things even more confusing. You had added a commit to your main, then merged that with the "real" main that did not have your commit, and somehow later on add copies of my commits from the branch to main (without doing a merge, i.e., in the "right way") anyway.

Well, no real harm done except that looking at this triggers my OCD. :-)

BTW, the main@{u} is the same thing as main@{upstream}, which just means whatever branch on the remote that your local main is tracking. It's just easier (or, perhaps in this case, not :-)) than going and fetching and then updating your local main branch to make sure it's up to date before using it. But it's probably not worth worrying about.

I don't have an Apple with slots myself (just a IIc, for space reasons), though I do have a couple of friends with a II or IIe that I could test this out with. But sadly, what I'm missing is a VCS, and I doubt I can get one here in Japan for less than several hundred dollars. (And it would probably have to be through Ebay; they're extremely rare here, though for some reason I managed to pick up a bunch of carts cheap a while back.) But as I mentioned, I've been thinking about doing an SRAM-based ROM emulator for a while, and the bidirectional communications idea is pretty attractive, so I'm very pleased now to see how to do that, too.

Actually, hm, I wonder if it would be worth doing something like this for a Famicom.
 

Attachments

  • this-is-a-merge-ha-ha.jpg
    this-is-a-merge-ha-ha.jpg
    45.7 KB · Views: 3
yeah, I forgot to rebase before I pushed an older commit I had made, oops. It won't bother me if you want to rebase and do a push -f to clean up the history.
My usual method of merging a branch locally is to 'git checkout thebranch', then 'git rebase main', then go back to main and 'git merge thebranch', which is what I did after that.
 
btb said:
My usual method of merging a branch locally is to 'git checkout thebranch', then 'git rebase main', then go back to main and 'git merge thebranch', which is what I did after that.
Click to expand...
Yes, so you're basically doing the same thing I suggested anyway, except that before that you really want to git fetch && git checkout main && git rebase to make sure your main is up to date. (On the branch, git rebase main@{u} is basically a shortcut so you don't actually need to update your local main: just use the upstream version.)
 
You must log in or register to reply here.
Back
Top