Inexpensive way to try out GALs?

[Kchula-Rrit]

No, I'm not talking about cruising the bars... 8-)

 

I've been trying to fit the parts to my cartridge schematic in the KiCAD board editor, but just can't seem to get them to fit.  Another user suggested using a programmable GAL to reduce the parts-count.  Sounds like a really cool idea, but the startup costs seem rather steep for something I'm not sure will work.

The parts aren't that expensive, but Microchip's programming cable is $90, and the software to do it is $300.  Their Web-site looks like the cable and software are particular to that one part.  Seems weird...

The Batronix BX48 EPROM programmer can supposedly program GALs, but it runs for $600!  My BX40 won't do it.

 

Ideas for a less-pricey option?

K-R.

 

Edited March 9 by Kchula-Rrit

[Gary from OPA]

5 minutes ago, Kchula-Rrit said:

No, I'm not talking about cruising the bars... 8-)

 

I've been trying to fit the parts to my cartridge schematic in the KiCAD board editor, but just can't seem to get them to fit.  Another user suggested using a programmable GAL to reduce the parts-count.  Sounds like a really cool idea, but the startup costs seem rather steep for something I'm not sure will work.

The parts aren't that expensive, but Microchip's programming cable is $90, and the software to do it is $300.  Their Web-site looks like the cable and software are particular to that one part.  Seems weird...

Ideas for a less-pricey option?

K-R.

 

when 8 designed my custom cartridges and my sob I used the gal 22v10 you can do slot with it, with the pop-cart i program the whole grom simulator in 2 gals and all the remaining bank switching logic in a 3rd one, with all 3 fitted nicely across the front and leaving room for the two large eproms at the back.

 

See this handy guide for more info:

 

http://www.s100computers.com/Software Folder/GALs/Intro To GALs.htm

 

I use my t48 programmer which is worth the investment as it does thousands of different chips and software to code up the gal there various free versions out there.

 

And as for microchip their wincupl should free:

 

https://www.microchip.com/en-us/products/fpgas-and-plds/spld-cplds/pld-design-resources

 

[Kchula-Rrit]

Thanks for the advice.  Looked at the S100 Web-site you suggested; didn't know any were still around.  I drooled over the thought of having an IMSAI 8080.  It was the first computer I ever used, aside from some masochism involving trying to run FORTRAN programs for a class using punch-cards.

Anyway, I did a Google search for GAL programmer and found a TL866-3G-T48 at Jameco for $69.  In the TI and the MiniPro TL866 EPROM Programmer conversation you mentioned getting a T48 with a pile of adapters.  Do you need an adapter to program GALs with yours?

May I ask, what is a "pop-cart?"

 

K-R.

[Kchula-Rrit]

Note: just found a description of the pop-cart...  Neat.

K-R.

[Gary from OPA]

14 minutes ago, Kchula-Rrit said:

Thanks for the advice.  Looked at the S100 Web-site you suggested; didn't know any were still around.  I drooled over the thought of having an IMSAI 8080.  It was the first computer I ever used, aside from some masochism involving trying to run FORTRAN programs for a class using punch-cards.

Anyway, I did a Google search for GAL programmer and found a TL866-3G-T48 at Jameco for $69.  In the TI and the MiniPro TL866 EPROM Programmer conversation you mentioned getting a T48 with a pile of adapters.  Do you need an adapter to program GALs with yours?

May I ask, what is a "pop-cart?"

 

K-R.

no you don't need the adapters if using dip versions. the adapters are handy for plcc chips like the rom flash on the ubergrom.

 

I need to update that page on my main website: https://garyopa.com/pop-cart/

i forgot i never put in the description for it. POP stands for Pile-Of-Programs

[+FarmerPotato]

56 minutes ago, Kchula-Rrit said:

 

Anyway, I did a Google search for GAL programmer and found a TL866-3G-T48 at Jameco for $69. 

The readily available chip is the ATF22V10. GAL is not made in the last 10 years.  

 

ATF22V10 is erasable.  It can functionally replace the old PAL/GAL chips (unless its faster speed is a problem.)  I starting using them with the TL-866-II, to combine 3-4 separate logic chips.  

 

You should get the DIP-24.  So far I use the PLCC-28 (for this you need an adapter on the T-48 or 56.)   After adding a PLCC socket, you don't save any board space vs DIP-24.  The thru-hole PLCC sockets make routing awful, so I now use the surface mount sockets.  Plenty of trouble there.    There is also an SOIC-24, which I will use when my design is final.  So you should try the DIP-24.

 

The WinCUPL software is a horrible experience.  I've learned its bugs, and I can get my parts programmed.  But the command line tools work fine on Windows, it's the GUI that should be avoided (Windows XP era).

 

The examples with WinCUPL are a decent introduction.   I learned from the barrel shifter example.  Most others are not for the 22V10.  There are old very good CUPL tutorials out there.

 

I can share more info & examples.  

[Gary from OPA]

This is a good reference book as well to learn more about how the insides of pals work and to build your logic.

 

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/935/1641.Designing_5F00_With_5F00_TI_5F00_Field_2D00_Programmable_5F00_Logic.pdf

1641.Designing_With_TI_Field-Programmable_Logic.pdf

Edited March 10 by Gary from OPA
added the pdf

[Kchula-Rrit]

48 minutes ago, FarmerPotato said:

The readily available chip is the ATF22V10. GAL is not made in the last 10 years.  

 

ATF22V10 is erasable.  It can functionally replace the old PAL/GAL chips (unless its faster speed is a problem.)  I starting using them with the TL-866-II, to combine 3-4 separate logic chips.  

That sounds like it's right up my alley.  I'm just generating some latch-write strobes and decoding RAM vs ROM.  The S100 site talks about using 22V10s, but his were from Lattice.

If nobody makes GALs, what do people use these days to do these kinds of things?  They sound so handy.

48 minutes ago, FarmerPotato said:

You should get the DIP-24.  So far I use the PLCC-28 (for this you need an adapter on the T-48 or 56.)   After adding a PLCC socket, you don't save any board space vs DIP-24.  The thru-hole PLCC sockets make routing awful, so I now use the surface mount sockets.  Plenty of trouble there.    There is also an SOIC-24, which I will use when my design is final.  So you should try the DIP-24.

I prefer using standard DIPs, as opposed to surface-mount.  However, I found out that I can, after all, solder surface-mount parts after helping the Better Half build a signal-generator kit a few months ago.  The DIP parts, at least, don't require an adapter to program them.

48 minutes ago, FarmerPotato said:

The WinCUPL software is a horrible experience.  I've learned its bugs, and I can get my parts programmed.  But the command line tools work fine on Windows, it's the GUI that should be avoided (Windows XP era).

 

The examples with WinCUPL are a decent introduction.   I learned from the barrel shifter example.  Most others are not for the 22V10.  There are old very good CUPL tutorials out there.

I downloaded WinCUPL a while ago; I can try to find the command-line version too.  Do the bugs relate to generating "bad" files, or is just a clunky user interface?  I have an XP system and a Win7 system available to me, along with various Linux machines.

48 minutes ago, FarmerPotato said:

I can share more info & examples.  

Thanks!  Would be much appreciated.

K-R.

[Kchula-Rrit]

9 minutes ago, Gary from OPA said:

This is a good reference book as well to learn more about how the insides of pals work and to build your logic.

 

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/935/1641.Designing_5F00_With_5F00_TI_5F00_Field_2D00_Programmable_5F00_Logic.pdf

1641.Designing_With_TI_Field-Programmable_Logic.pdf 814.35 kB · 1 download

Thanks!

I downloaded it and will take a look, when my eyes recover from reading this screen.  The company I worked for in the 1980s used PALs in a computer they were developing; the main thing I remember is that the PALs ran VERY hot and had a high failure rate.  I assume the 22V10s are better in that regard.

 

K-R.

[Gary from OPA]

10 minutes ago, Kchula-Rrit said:

Thanks!

I downloaded it and will take a look, when my eyes recover from reading this screen.  The company I worked for in the 1980s used PALs in a computer they were developing; the main thing I remember is that the PALs ran VERY hot and had a high failure rate.  I assume the 22V10s are better in that regard.

 

K-R.

Most of the failures I see over the years been related to random static discharge or in the case of TI99 pulling out a peb card to early after shutting off the power. Pals used on corcomp cards and their love of using tms9901 as well suffered that fate. Not sure about running too hot.

 

I have not yet tried the replacement ATF22v10 but I sure it's more reliable besides also being faster. Plus you can erase easier than back in the day with uv eraseable ones those I found less reliable.

Edited March 10 by Gary from OPA

[RickyDean]

47 minutes ago, Kchula-Rrit said:

That sounds like it's right up my alley.  I'm just generating some latch-write strobes and decoding RAM vs ROM.  The S100 site talks about using 22V10s, but his were from Lattice.

If nobody makes GALs, what do people use these days to do these kinds of things?  They sound so handy.

I prefer using standard DIPs, as opposed to surface-mount.  However, I found out that I can, after all, solder surface-mount parts after helping the Better Half build a signal-generator kit a few months ago.  The DIP parts, at least, don't require an adapter to program them.

I downloaded WinCUPL a while ago; I can try to find the command-line version too.  Do the bugs relate to generating "bad" files, or is just a clunky user interface?  I have an XP system and a Win7 system available to me, along with various Linux machines.

Thanks!  Would be much appreciated.

K-R.

Gals can still be purchased from the electronic outlets, like Mouser, and such, their not dead yet. But the ATF's can be used too. You can still purchase Pal's on Jameco and ebay.

[matthew180]

22 hours ago, Kchula-Rrit said:

No, I'm not talking about cruising the bars... 8-)

 

Arguably a better use of time... 😄

 

22 hours ago, Kchula-Rrit said:

but Microchip's programming cable is $90, and the software to do it is $300. 

 

That's crap.  The tools should be free!  If Microchip is charging for software to program their chips, then its time to find something else.  As others have mentioned, the older PALs and GALs were programmable via standard IC programmers.

 

Parts like the Atmel ATF16V8 series are $1.25 on Mouser and are programmed with a standard chip programmer.  The 16V8 has been around a long time and has enough logic to do a bit of address decoding and such.

 

17 hours ago, Kchula-Rrit said:

If nobody makes GALs, what do people use these days to do these kinds of things?  They sound so handy.

 

The world moves on, and the older tech is going to get a lot harder to find.  What people are using these days depends, but mostly they are hacking ready-made microcontroller boards like the Arduino, Rpi, AdaFruit tinsy, etc..  These days, for less than the price of a GAL ($1.25) you can get a dual-core 133MHz ARM core RP2040 ($0.80).  And it sure as hell is hard to beat the $5 cost of the RP2040 already on a circuit board with support regulators and such.  You might as well just buy the RP2040 board, stick it on your cartridge board, and call it a day.

 

However, for retro-computing the biggest problem with the new stuff is interfacing with the 5V systems.  Almost everywhere you will need protection for the inputs to the 3.3V (or lower) chips, which is where the older GALs still have an advantage.

 

Newer chips are also usually designed to be in-circuit programmed, since flash memory is cheap and added to almost every embedded chip these days.  The MCUs also come with hardware support for storage (like SD cards) and USB, which makes in-system programming even easier.

 

You might as well not even consider price for a project like this, since the most logical or oldest-tech solution will not be the cheapest solution.

 

Also, for $6 to $8 you can get an FPGA with enough capability to implement the entire computer, let alone something as simple as cartridge address decoding and logic, flash memory (or any other kind of memory) interfacing, etc..  And the $8 chip has built-in flash, so you don't need an external flash IC to load your bitstream.  These would be the Trion T8 and T13.  I'm having to change the F18A over to this line of FPGA because they are cheaper and more available than the Xilinx FPGAs these days (seems Xilinx does not want to be in the low-end FPGA business any more... which is a bummer).  It is still hard to justify over the RP2040 though, that chip is just so cheap, and probably fast enough (maybe).  Anyway, I digress.

 

If you stick with surface mount components, then you can also have places like JLCPCB manufacture and assemble the boards, generally for less than you can buy the parts and assemble them yourself.  This is the way.

 

Edited March 10 by matthew180
spelling

[+FarmerPotato]

9 hours ago, Kchula-Rrit said:

downloaded WinCUPL a while ago; I can try to find the command-line version too.  Do the bugs relate to generating "

It's the same package. The GUI runs the command line tools to compile. You can type the commands yourself. 
 

The WinCUPL GUI has the most bugs around reading/writing files and refreshing the screen. It gets stuck complaining about something you can't see. (Then it crashes.) The Winsim simulator GUJ is also bad at showing you changes to the screen. 
 

I just rely on the text files. 

 

[atrax27407]

Here are some docs and cross-references that might be of use:

Lattice GAL Cross Reference.pdf LATTICE GALs Discontinued.pdf PAL Cross Reference.pdf

[TheMole]

One could use an EPROM as a sort of programmable address decoding chip. Imagine a 64kb EPROM programmed to output different chip select lines on its data bus for different addresses.

[atrax27407]

Here is another group of programs for converting PALs to GALs and other stuff.

OPALJR21.zip

[Stuart]

1 hour ago, atrax27407 said:

Here is another group of programs for converting PALs to GALs and other stuff.

OPALJR21.zip 647.81 kB · 1 download

That's the package that I use for programming GALs. Needs to run on a 32-bit (or lower) OS or DOS - I use a DOS command prompt in a 32-bit Windows VM. No joy in 64-bit Windows (although you might be able to do something with the ‘Compatibility’ settings).

[Kchula-Rrit]

2 hours ago, TheMole said:

One could use an EPROM as a sort of programmable address decoding chip. Imagine a 64kb EPROM programmed to output different chip select lines on its data bus for different addresses.

I did exactly that when I built a 32K expansion in 1984.  Used a 74S288 to decode the address lines and the whole thing was point-to-point wiring, made of parts I got from an electronics surplus store.  I could boil a pot of spaghetti on that thing.  Was amazed that it worked the first time!

K-R.

[Kchula-Rrit]

1 hour ago, Stuart said:

That's the package that I use for programming GALs. Needs to run on a 32-bit (or lower) OS or DOS - I use a DOS command prompt in a 32-bit Windows VM. No joy in 64-bit Windows (although you might be able to do something with the ‘Compatibility’ settings).

May I ask, which programmer did you use to program the chips?  I found a TL866-3G-T48 at Jameco that lists GAL {16V8-B-D, 20V8-A-C, 20V10-A-C-D} in its supported devices list.

K-R.

[RickyDean]

The MinipPrp TL866 programmers, come with a Windows based programming enviroment. You can pick and choose the devices you are dumping and programming to include whatever GAL chips are in the list. For a Gal, you just need the *.jed file for the  programmer, load it in and hit the program button. 

Now to get to the jed file requires some work, for example dumping the Pal chip for a Geneve VDP, requires a device, like a DuPal decoder, to decode the inputs and outputs of the Pal, then a step to convert that information into an equation that is then converted into a jed file to be programmed into a Gal. That's where I'm stuck at, for the moment as I've been busy with other things and haven't learned that step yet. But if the Jed files are already available like the ones that Fritz442 has posted here on thes forums, then you can burn those easily with a  TL866 programmer.

Edited March 10 by RickyDean
spelling

[Kchula-Rrit]

20 hours ago, matthew180 said:

...

The tools should be free!  If Microchip is charging for software to program their chips, then its time to find something else.  As others have mentioned, the older PALs and GALs were programmable via standard IC programmers.

I totally agree!  If these companies wish to encourage people to use their products, the tools to do so should be inexpensive, if not free.  Of course, their definition of "inexpensive" likely differs from mine...

20 hours ago, matthew180 said:

Parts like the Atmel ATF16V8 series are $1.25 on Mouser and are programmed with a standard chip programmer.  The 16V8 has been around a long time and has enough logic to do a bit of address decoding and such.

I have the supported-device list for the T48 that farmerpotato uses.  It finally occurred to me to search for "ATF" instead of "GAL" to see what devices are supported.  Lots of ATFs!  I've been fixed on GALs for some reason.

20 hours ago, matthew180 said:

 

The world moves on, and the older tech is going to get a lot harder to find.  What people are using these days depends, but mostly they are hacking ready-made microcontroller boards like the Arduino, Rpi, AdaFruit tinsy, etc..  These days, for less than the price of a GAL ($1.25) you can get a dual-core 133MHz ARM core RP2040 ($0.80).  And it sure as hell is hard to beat the $5 cost of the RP2040 already on a circuit board with support regulators and such.  You might as well just buy the RP2040 board, stick it on your cartridge board, and call it a day.

I see what you're saying, and I realize I'm probably "living in the past."  I would like to think that there's room for multiple levels of complexity (lack of a better word).  The Raspberry Pi Zero is silly inexpensive but for my needs, it would be like driving a semi to the grocery store to pick up a carton of milk.

20 hours ago, matthew180 said:

...

You might as well not even consider price for a project like this, since the most logical or oldest-tech solution will not be the cheapest solution.

I'm finding that out.

20 hours ago, matthew180 said:

Also, for $6 to $8 you can get an FPGA with enough capability to implement the entire computer, let alone something as simple as cartridge address decoding and logic, flash memory (or any other kind of memory) interfacing, etc..  ...

I remember some time ago somebody had a "TI that ran Linux," that was a TI shell with a Raspberry Pi in it that looked (presumably) acted like a TI.

20 hours ago, matthew180 said:

If you stick with surface mount components, then you can also have places like JLCPCB manufacture and assemble the boards, generally for less than you can buy the parts and assemble them yourself.  This is the way.

You're probably right about this one, too.  Right now, I'm only looking at a few boards for my own use  I don't know if this project will appeal to the community at large, but I can dream...

 

K-R.

[Kchula-Rrit]

I wish to thank everyone for the information and advice.  I have a lot to go through!  My training was in hardware, but I've picked up some programming over the years.

Thanks, Gary from OPA, for the TI Designing PDF.  It's fascinating, but my eyes started to glaze while reading through it.  Still trying to wrap my head around how they set-up the Karnaugh maps in the counter example (the first one).  Haven't seen a Karnaugh map in literally half a century!  That led me to Wikipedia to refresh my memory, which led me to Gray codes.  At least I figured-out how to do a n-bit Gray code.

Thanks, atrax27407, for the OPAL software, and to farmerpotato for the CUPL/WinCUPL.  I went over to the S100 site and snarfed what info and software I could.

 

Just realized I sound like Dorothy at the end of the Wizard of Oz.  I'll stop before this gets too creepy.  8-)

 

K-R.

[Stuart]

16 hours ago, Kchula-Rrit said:

May I ask, which programmer did you use to program the chips?  I found a TL866-3G-T48 at Jameco that lists GAL {16V8-B-D, 20V8-A-C, 20V10-A-C-D} in its supported devices list.

K-R.

I'm still using a 'Genius' G540. Was quite popular until the TL866 came out.

[matthew180]

13 hours ago, Kchula-Rrit said:

I see what you're saying, and I realize I'm probably "living in the past."  I would like to think that there's room for multiple levels of complexity (lack of a better word).  The Raspberry Pi Zero is silly inexpensive but for my needs, it would be like driving a semi to the grocery store to pick up a carton of milk.

 

We are all in the past here.

 

It is hard to convey intent with text, so my comment probably came across a little wrong.  I agree with you, and I like to imagine using just enough technology to solve the problem.  However, that is getting harder and harder to do, and we find ourselves in a situation where the smallest, cheapest, and best supported (software and vendors) solutions are battle axes with 1000x more capability than needed.

 

Want to blink and LED?  Get a 133MHz MCP with USB interface, download a 500MB IDE onto your 8GB operating system, fight with USB drivers, download an I/O library and a framework, find the right location in a 100 line "simple example" template, write 3 lines of code, compile, upload to your MCU, reset and bask in the glory of a blinking LED.

 

That crap drives me nuts!  But that is how things are now.  Going against the grain is painful (I do it all the time, and I'm probably very miserable for it).

[hhos]

On 3/10/2024 at 12:20 PM, TheMole said:

One could use an EPROM as a sort of programmable address decoding chip. Imagine a 64kb EPROM programmed to output different chip select lines on its data bus for different addresses.

Trivia that isn't on topic: I don't think most EPROMs would be fast enough to do that, but Williams Electronics used some smaller, very fast memories to strobe pixels to the screen in their video games.  They are 7489s,74189s, etc.  Also, for the cocktail tables models there was a larger one that gave line numbers so flipping one bit in the hardware flipped the entire display around to the player on the opposite side. 🙂  The 74LS612 is another example of this used primarily for memory management. (Super AMS)

HH

Edited March 11 by hhos
Added another example