6502.org

They're forced to compromise because they only had 40 pins to work with. In order to offer the on-chip clock generator (as in the non-E version) they had to forego other functions because there aren't enough pins to do it all.

I've just been perusing the ol' Moto manual, and I see the E version features the following signals not offered on the non-E version: TSC (same as 65xx BE or Bus Enable), LIC (which is somewhat SYNC-like), BUSY and AVMA (whose functions I have yet to learn).

If none of those functions is important to you then the non-E is a better choice; there'll be no need to supply an external oscillator and clock generator. Luckily, said external circuitry isn't that complex, and it's not that big a deal if you need to go the E route.

Currently looking at the Hitachi 63x09E datasheet: So I guess the reason for using the 'E' variant in the CoCo computers weren't BUSY and AVMA, but TSC (and maybe LIC).

I see, there were variations on the Q & E. The spec sheet I looked at must have been one of the versions using them as inputs. All a little confusing.
Which part is the easier to get?
Dwight

Oh, okay. I had a strong feeling there was some confusion somewhere. I'd forgotten about the E variant -- thx, Martin A, for bringing it up.

These chips are no longer in production but are still possible to obtain, or so I've heard. Compared to the Motorola chips (6809, 6809E), Hitachi's (6309, 6309E) have a long list of advantages; see the Wikipedia 6309 page for more detail.

For my 6809 project I recently bought a couple of 68B90E's via eBay (after getting click-happy and accidentally buying the slower 6809E's first...

I also ran across a site that sells vintage chips http://www.unicornelectronics.com/IC/6800.html.

Well,to go back to the very subject of this topic,the Sym-1/69 binaries and the Addendum's copy ought to be added to the Sym-1 archives,don't you think so ??
There was also a 6802 variant called Sym-1/68.Any taker here ??

Thanx again , Rene'.

Hi again,
bought 4 Tesla mh74s287 (82s129) from Bulgaria and the vendor offers me to program them if i send him the bin file.
Those proms are easy to read but programming them is another story : same name but # protocol....
I'm not sure i would correctly define the prom contents so if any of you is able to read the onboard 82s129 or 74s287 prom,
please,do so.
I do not need the 4 proms only 2 and the 2 other will be avail for a nominal fee.

Have a nice day , Rene'.

Attached is the binary image of the 82s129, as read from my Sym-1/69.

I have no way of confirming if this is totally accurate, as my Eprom programmer does not directly support the 82s129.

I had to make an adaptor, read this as a 2716, then crop the upper 768 bytes of mirrored code.

However, looking at the image reveals groupings of 0xF0 and 0xF1, which is what I would have expected, given the Data line D0 is being fed via the And gate to the 6502.

Someone out there might be clever enough to check the F0 and F1 mappings, to see whether these appear to fall within the correct boundaries for the Monitor, IO and zero page.

Nice of you to make the effort, andysa. And the data checks out. Page 2-11 of the Sym1-69 manual says the addresses excluded from single-step are page $00, page $01 and page $FF as well as the monitor and I/O areas. Your binary file from the PROM contains $F0 in locations $00, $01 and $FF, and as you say it's only the least-significant bit that's meaningful. $F1 means Single-Step is enabled; $F0 means not.

The monitor and I/O areas check out as well. The chart on page 4-18 of the SYM-1 Reference Manual shows pages $80-$8F as the 4K monitor ROM and pages $A0-$AF as the I/O area; all the corresponding locations in your PROM contain $F0. (And all other PROM locations are $F1.)

@esarintulo, we obviously haven't assembled a complete schematic yet, but it looks as if the hardest parts have been solved -- such as the PROM connections andysa posted here. Notice that the diagram I posted shows 6502 IRQ\ attaching to 6809 FIRQ\, but that was a choice I made when it seemed we would have to reinvent everything anyway. Instead now we're reproducing the original, and I'm pretty sure that means 6502 IRQ\ will attach to 6809 IRQ\ (not FIRQ\). Really all the connections I suggested should be verified by referring to the PCB photos andysa posted.

-- Jeff

The two binaries in the above attached zip file are marked as high as low ..does anyone know what is the actual memory address of each of the eproms ..is it the same as the 6502 monitor?

Will it really be a problem for you if the addresses don't match the 6502 configuration?

Upthread you'll find some doc attached. The Sym-1/69 Supplement attached to this post lists monitor entry points. And the installation instructions here mention changing some links on the mobo when the new EPROM's go in. To understand whether and how those links affect EPROM mapping just locate and consult the original (ie, 6502) SYM Manual.

Tnx for that .. I did not look through all the Sym-1/69 docs ..just pickup up on the two binaries for the 6809 .. marked high and low .. the reason I am asking is that I did a SYM-1 Maxi pcb ..which reasonably resembles the SYM-1 board (in functionality) which seems to run Ok so far ...with things like the monitor and basic ... yet to try out RAE .. that one is obviously a 6502 based .. but I should be able to redo the pcb and make it a 6809 version ..then that new version should be a copy (in functionality) of the Sym-1/69 version .. without trying to do any mods to this pcb

https://sites.google.com/site/gogleoops/sym-1-maxi

Nice lookin board you've got there!

And a 6809 variant would be nice, too. However, you could alternatively just do a daughterboard that plugs a 6809 into the 6502 socket.

There's still the question of what those links on the original SYM do. I located that SYM manual, BTW -- turns out I saved a copy. Here it is.

Tnx .. I already have that info ..some of that is already on the 6502.org site .. redoing the board is not too much of a hassle ..just getting all the info correct before it is made.. the Maxi board is larger than 100x100mm ..in fact it is 120x120mmm which makes it bit expensive to make .. I am referring to 100x100mm board ..since that size or smaller ..for some reason (from China makers) .. you can get those boards rather cheap and FREE DHL postage ..which means from design and submission of gerber files you get 10 pcb's for $5 within a week .. that would mean reducing at least one of the components ..for 100x100 design .. but maybe I'll cop it and do a larger version having the 6809 on it

I like the 6809 chips .. I reckon one of the top micros of its time...