Fast prototyping boards

[BillO]

Just trying to get input from the group on an idea.

The idea is to create a series of fast prototyping boards for various CPUs.

All boards would have pre-wired CPU to memory and I/O device address, data and timing/control (each where appropriate and applicable) and would allow for several different memory and I/O configurations. There would also be a large prototyping area to allow for custom device selection logic and other custom items. In this way, almost any possible memory map and I/O could be quickly configured without the mind-numbing and error prone process of hand wiring the bussed signals.

As an example, the 6052 derived board would have space for a 6502 and an oscillator, maybe 4x28 pin memory devices, 2x6522's, a 6551 with max232, pads for 2x16 pin TTL, 3x14 pin TTL with pre-wired power and bypass caps then a fully uncommitted area for standard dip packages with VCC and GND busses. All address, data, control, timing and CS lines would terminate close to the prototyping area and have multiple connection points. In addition, 2 of the memory device areas would have enough room for ZIF sockets, to ease firmware development. A suitable power filtering and regulating circuit would also be provided. The 6522 I/O ports would go to header areas and the max232 to a DB9 layout.

I know the boards are likely to be larger than what is ideal for a finished product, but the potential time saved in development would be considerable, and in many cases the boards could be used as-is if space is not a major concern.

All just ideas right now.

Thoughts?

[Nightmaretony]

DArryl's SBC-1 was a pretty good prototyping platform. Still doing my own generic bugger with a CPLD and banked rom and ram.

Addressing: CPLD madness?

but for various cpus, yuppers. A generic edge such as VME?

[GARTHWILSON]

Daryl (8-bit) has been providing boards which aren't far from what you say.  I don't think there will ever be a do-everything board though.

If you want to make such a board and offer it to anyone who wants it, I'd say "Go for it."  Many years ago, we used to have these discussions about making a 6502 computer board for sale to the forum members, and every time, it would turn super long and there would be no agreement on what it should consist of.  Usually the idea was that as long as we're doing it, we should add this and that and everything else imaginable to try to make everyone happy, and it became unrealistic to ever get it made.  After a few of these, I think everyone knew it was futile to start a new discussion on that.  Then Daryl made a board without consulting everyone, and told us what it had and said "You want one?" and quite a few people ordered.  It was very close to what you're describing, minus the prototyping area (which a board manufacturer will probably charge you extra for because of all the drilling).

I have the 4Mx8 5V SRAM module available (data sheet here) and I want to do more such modules to reduce the size of the job of making hobby computers.  The easier we can make it, the more people will be attracted to dive in, promoting our common interest and the interest group.

[ElEctric_EyE]

BillO wrote:

Just trying to get input from the group on an idea....
All just ideas right now.

Thoughts?

5V or 3.3V? heh

[Nightmaretony]

Perhaps the sub modules being standardized. The I2C of Lee's turned into an easilty accesible. Garth, your RAM module. A CPLD video module. Want our own peripheral standards for plug and play out here?

[GARTHWILSON]

Quote:

The I2C of Lee's turned into an easilty accesible.

Do you have a link? I never saw it. Daryl and I have an I²C pinout for a keyed, inexpensive, easily available 6-pin header that fits into standard perfboard (unlike the one that someone in New Zealand came up with and was trying to make standard), but since almost nothing has been made for it yet, certainly we want to know about Lee's. We use 5 of the 6 pins: ground, Vcc, clock, data, and IRQ\, with the 6th pin being cut off and the hole in the socket plugged to avoid plugging in upside down. The IRQ\ line allows for example an RTC (real-time clock) IC with alarm output, keypad controller that interrupts when a key is pressed, etc..

There is of course also the 65SIB (6502.org Serial Interface Bus) which can be used for tons of things. I also want to make little boards that hold the 65SIB pin headers and relieve the builder of the labor of wiring those up along with the voltage regulators and maybe even level shifters for different logic voltages.

[Tor]

Nightmaretony wrote:

but for various cpus, yuppers. A generic edge such as VME?

heyheyhey, I've got an unused VME crate here (several actually, if I go down to the waiting-to-be-discarded bin). And power supply and everything. I haven't found anything to use it for, yet..

-Tor

[Nightmaretony]

http://members.multimania.co.uk/leeedav ... index.html

Figure it can swing into a 65C22 somewheres....

[GARTHWILSON]

Nightmaretony wrote:

http://members.multimania.co.uk/leeedavison/6502/i2c/index.html

Figure it can swing into a 65C22 somewheres....

Ok, so it does not cover the connector itself, which is all Daryl and I specified. I'll look up our pinout and come back and post it. Lee says on that page,

Quote:

There is no socket shown for the I2C bus, [so] this is up to the user.

I have used the 65c22 for I²C. To do the input and open-drain output on the same pin, you just write a 0 to the bit in the output register and then 0 or 1 to the bit in the data direction register. A "1" output is the same as input, ie, data direction register bit being a "0" for input so it doesn't pull the line down.

[BillO]

GARTHWILSON wrote:

Daryl (8-bit) has been providing boards which aren't far from what you say. I don't think there will ever be a do-everything board though.

The intent would be that these would come pretty close, so flexibility over features. As well as what is mentioned previously, the full CPU bus could be offered with the option of buffering.

Seeing as how WDC stay in business, there must others besides this group that could use such a thing.

After the 65C02 board, others would follow, such as a 6809, Z80, 65C816, others...

GARTHWILSON wrote:

I have the 4Mx8 5V SRAM module available and I want to do more such modules to reduce the size of the job of making hobby computers. The easier we can make it, the more people will be attracted to dive in, promoting our common interest and the interest group.

What is the interface? Does it allow bank switching, or is it intended for the 16 bit CPU?

[BillO]

ElEctric_EyE wrote:

5V or 3.3V? heh

Boards would be unpopulated, so whatever works for your design. Is there a 3.3v 65C02?

[BillO]

Nightmaretony wrote:

Addressing: CPLD madness?

CPLD's are great! But on these boards, the choice would be up to you. The addressing is the one thing that must remain completely custom. It is really what separates designs.

[ElEctric_EyE]

BillO wrote:

...Is there a 3.3v 65C02?

Yes there is!
The CMOS WDC65C02 data sheet FMax vs VDD chart on Pg.25 starts with 1.8V @ ~2MHz. 3.3V @ 14MHz. There is no spec for 5V...
I have run it powered with 3.3V @ 20MHz on my old project, however I was not loading the processor...

[GARTHWILSON]

BillO wrote:

Seeing as how WDC stay in business, there must others besides this group that could use such a thing.

I'm not sure what you mean there, because they make most of their money by licensing IP, not selling ICs.

BillO wrote:

GARTHWILSON wrote:

I have the 4Mx8 5V SRAM module available and I want to do more such modules to reduce the size of the job of making hobby computers. The easier we can make it, the more people will be attracted to dive in, promoting our common interest and the interest group.

What is the interface? Does it allow bank switching, or is it intended for the 16 bit CPU?

It's mainly intended for an 8-bit bus, but you could put two together for 4Mx16. The main page on it is viewtopic.php?t=1908 , with the list of features about 2/3 of the way down the page. I'll post a data sheet soon. (Edit, months later: I forgot. Here it is.)

Quote:

Is there a 3.3v 65C02?

Current-production ones will work down to 1.8V, although dropping from 5V to 3.3V slows them down a little, and dropping to 1.8V slows them down a lot.

http://WilsonMinesCo.com/

[BillO]

GARTHWILSON wrote:

... they make most of their money by licensing IP, not selling ICs.

True, but they do sell a fair number of ICs and are interested in increasing that business. I just got an email the other day from David Gray offering me a few W65C51NTPG-14s as samples. They now have them in both DIP and PLCC packages. BTW, they are still only available as samples, but they are eager to get them to market. However, anyone waiting on this one may have to wait a little longer.