The R65C19 was produce mainly for PC MODEMS. I had used the R6501Q for some controllres in the '80's & when I talked to an app engineer at Rockwell in the early '90's, he recommended using the ROMless version of the R65C19. Unfortunately, the project was canceled. I still have some samples around ...

I found an article in an old book I've got "The Best of Micro Volume 1".
"Micro" was a magazine in the late '70's & early '80's that civered all the many different 6502 based systems. KIM-1, AIM-65, PET, Apple II, SYM-1, Super JOLT, Challenger II, & whatever.
The article expains what the TIM is ...

I don't believe there' any source for them. I've searched the internet for them several times. I've got several controller boards that use the R6501Q.

The 64 pin device that has the FORTH kernal is the R65F12Q. There was also a 40 pin device, the R65F11P. They both have all the Runtime FORTH in on ...

ccording to my Rockwell book, there are 8 cycles involved in the NMI.
1 Fetch OP Code Hold Prog. Ctr, Finish Prev Operation
2 Fetch OP Code Hold Prg Ctr
3 Push PCH Decrement Stack Pointer
4 Push PCL Decrement Stack Pointer
5 Push Processor Status Decrement Stack Pointer
6 Fetch Vector Low ($FFFA ...

I agree that will work, but if anyone tries to trouble shoot the board ... ? Isn't this just a way to make reverse engineering more difficult ?:) Just try & disasemble that program. If you're wire wrapping, I don't see a benefit. If you're laying out a PCB, what's 1 or 2 more VIA's
Ted Melton

I checked out the Atmel parts. They look interesting. What's the avalibility & price of these parts ? Are you using them for DATA storage only ? Or is there some way to use them for Program Code ? Like boot with a small EPROM, & then copy from the Atmel part to RAM & then run from there ? How would ...

Do you have any website references to these serial flashparts ? I had thought about using flash parts, but I haven't had the time to do the research. I think that would be a good solution for industrial controllers & data acqusition.
Ted Melton

All the boards I got from Rockwell & DynaTem had a 4MHZ crystal & a 74HC74 to divide it to 1MHZ. The DynaTem boards also had jumpers so that the board could run at 2MHZ.
Until I read your Tip I really never thought of connecting a crystal directly to the 6502. I remeber looking at the DATA sheet ...

>Do you know the publisher or where it's available?

Try looking at Don Lancaster's web site, "The Guru's Lair". It's at www.tinaja.com . If you haven't been to this one, it's a treat. He has all the books that he's written ava., copies of all the magazine articles he's written over the many years ...

Somewhere I've got a app. note from Rockwell on how to do that. I'll try & dig it up.
Ted Melton

No, I don't know of any EPROM's fast enough. What was used in the old S-100 Bus systems was a "wait state generator". It would hold "RDY" for one or two clocks to allow the "EPROM" to respond. I had thought of using something like this & what the PC motherboards call "Shadow RAM". Boot up with slow ...

I've got the Windoze Version of the Schematic Capture & the last DOS Version of the PCB Layout. I really love the Schematic Capture. It's very friendly & easy to use. The PCB Layout seems to work fine. I've done several boards with it down to some tiny SMT boards.

There's really no reason for the ...

Why do you want such a small ROM to boot from ? The size you asked about are in a 16 pin DIP, a 2716 (2K x or 2732 (4K x are in a 24 pin DIP. That's about the shallest for an EPROM. The ones in a 16 pin DIP are OTP (One Time Programmable), a little expensive for developement.
Ted Melton

Jameco Electronics has 74S287 (256 x 8) & 74S472 (512 x 8) PROMS in stock. I'm not sure about programming them. The only tim I used them was for address decoders, many years ago. I had a local electronics destributor program them.

Have you thought of using a serial EEPROM like a 24C02. They're much ...

Good to hear from you. I had a very busy few months at work. (80 hour weeks really kill you.)
I missed out on your bulk order from WDC. And I haven't seen much on the SBC design. The last few weeks I've been trying to catch up. Over the holidays I went back & re-read all of the posts on the design ...