VIC 1112 IEEE Interface

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dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Tue Nov 15, 2016 5:10 pm

OK, well, I thought we were done, but here we go:

I said it would be cheaper to refund you because it would be, this is the SECOND card I sent you and I sent it before your profanity laced tirade. So sorry I sent you something you so desperately wanted, my bad. I am happy to post the full contents of EVERY PM, as I keep them all just for cases like this. It typically infuriates the person who is already upset, but if thats what we are doing, I am happy to oblige. The shipping receipt for your SECOND CARD was posted, the admin removed it, feel free to browse my flicker feed for it Renato...

Yes I socketed the whole board. who can fault me for that? I said, and I quote
But the hex bus inverters tend to fail over time (not alot, but it happens in PETs fairly regularly)


OVER TIME. not initially, you wouldn't prefer to have it be a user replaceable part rather than a desoldering mess if, god forbid, you zapped it with static electricity? (note: I am not saying this board is any more sensitive to static electricity than the next, but I must point out all facets of my decision apparently) I did imply they die regularly in PETs. And that is in fact true, they are 40 years old, so its not unheard of. again, I socketed every chip, would be cheaper not to, but, in the interest of longevity, I did it anyway....

Now, to publicly try to say these boards don't work? I am speechless, EVERY board has worked, from the very first prototype to the last one assembled. Jesus man, wtf is your problem? I get you are upset about the postal system and my perceived ignoring you (again, I do not live to post on this forum, as I actually do other things) but to make baseless allegations is childish and transparent.

Get some help, seriously....
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dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Tue Nov 15, 2016 5:13 pm

And since we are addressing things, it should be clear to everyone that the poster known as VIC-1112 is not actually a backer, since when confronted with the chance to prove it, he declined and stopped responding when the refund offer was extended. And for someone encouraging the reporting of a kickstarter, noone has. Odd, as only a backer can report it. FYI, I won't do a kickstarter again, certainly haven't needed it for any of my other projects, more fun when they are developed in secret anyway :)
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eslapion
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Re: VIC 1112 IEEE Interface

Postby eslapion » Tue Nov 15, 2016 5:56 pm

dragos wrote:Yes I socketed the whole board. who can fault me for that? I said, and I quote
But the hex bus inverters tend to fail over time (not alot, but it happens in PETs fairly regularly)


OVER TIME. not initially, you wouldn't prefer to have it be a user replaceable part rather than a desoldering mess if, god forbid, you zapped it with static electricity?

TTL chips are practically insensitive to static electricity. What mostly destroys 7407, 7406 and other open-collector output logic chips is when they are used as non conflicting communication chips and the devices which use them gets connected while powered or having substantial ground level differences.

Protections against that were implemented in the C64c.

(note: I am not saying this board is any more sensitive to static electricity than the next, but I must point out all facets of my decision apparently)

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dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Tue Nov 15, 2016 6:31 pm

BTW, take a cue from Eslapion. We do not always see eye to eye and have had our differences, but he doesn't jump right into the mud pit....

I personally have never static zapped something, but I have to mention it or someone may purposely do it and say I didn't warn them :)
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Kakemoms
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Re: VIC 1112 IEEE Interface

Postby Kakemoms » Thu Nov 17, 2016 11:23 am

dragos wrote:BTW, take a cue from Eslapion. We do not always see eye to eye and have had our differences, but he doesn't jump right into the mud pit....

I personally have never static zapped something, but I have to mention it or someone may purposely do it and say I didn't warn them :)


I didn´t make the mud here, but I take the point.

If there are no static protection in place, that can certainly take out all the chips, not only the inverters. A simple diode is usually some protection against that, but due to the long cables it may be wise to put them on every input.

dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Thu Nov 17, 2016 3:16 pm

ok, but just to be clear. The clone (or re-imagining) is 100% based off the original 1112, in fact the prototype run was the original layout with jumpers in place of solder pads. We made a few changes to the layout for the production run, and removed some of the jumpers that were not needed. So the chips in general are not at any more risk than the original, which I think we agree are relatively durable but have been know to fail after a number of years.

here is a pic of the original cart and prototype #1

Imageimage by markgladson, on Flickr

The mc3446n that are being used are NOS I buy them 50 at a time.

If I can fit it in a cart case with sockets, I typically socket everything, its just easier in the long run.
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Kakemoms
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Re: VIC 1112 IEEE Interface

Postby Kakemoms » Sat Nov 26, 2016 5:44 pm

Well, hooray, I finally got your pcb.

After some searching to steal two 6522 from other systems, I burnt your image to a NEC 2764C-4 PROM... and nothing.

Well after fiddling around I could see the ROM code at 45064, but with all data looking like %0xxxxxxx. E.g. The D7 line seemed shorted to ground.

I rechecked the PROM in my programmer, checked the pcb but to no success.. Data was fine in the programmer but not in my Vic's. I finally tried a M27C128 UV EPROM instead and it worked!

Well, at least the software. I couldn't get much response from the drive, but that might be one of the 6522 which was really old. I will replace that with some R65C22 i think.. sounds like the WDC 65C22 is slightly different without pullup resistors inside? Will that matter here?

dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Sat Nov 26, 2016 8:32 pm

There are two versions of the WDC 6522:

W65C22S/W65C22N Differences

The W65C22S is lower power, faster and direct drive outputs with no current limiting resistors on outputs ports.
The W65C22N is plug replacement of NMOS 6522 devices with current limiting resistors on output ports.
The W65C22N does not have bus holding devices on the input, IO pins.
The W65C22N IRQB is an open drain output that CAN be Wire-ORd, unlike the totem-pole output of the W65C22S (some customers have had to use a diode in series with the IRQB output when using the W65C22S in their systems that had Wire-ORd interrupts).


so the 65c22n is the one you want. It should not have any issues as I personally use these in mine!

on the initial rom issue, check the jumpers the should be vertical for a real eprom and horizontal for a 29 series flash chip.

I personally use 28c64 in all the boards as the cart has the ability to flash the eeprom in the vic (software not yet written, but on the todo list) as well as software write protect!

if you are not getting a repsonse, it is 99% likely it is one of the 6522s, I had several bad ones in my original testing.

Glad you got the cart!!!
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eslapion
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Re: VIC 1112 IEEE Interface

Postby eslapion » Sun Nov 27, 2016 4:23 am

Kakemoms wrote:Well, at least the software. I couldn't get much response from the drive, but that might be one of the 6522 which was really old. I will replace that with some R65C22 i think.. sounds like the WDC 65C22 is slightly different without pullup resistors inside? Will that matter here?

:shock: NOOOooo!!!

The R65C22 is a Rockwell made CMOS version of the 6522 that uses a totem-pole outpout on IRQB and this can cause short circuits. DON'T TOUCH THAT!

dragos wrote:W65C22S/W65C22N Differences

The W65C22S is lower power, faster and direct drive outputs with no current limiting resistors on outputs ports.
The W65C22N is plug replacement of NMOS 6522 devices with current limiting resistors on output ports.
The W65C22N does not have bus holding devices on the input, IO pins.
The W65C22N IRQB is an open drain output that CAN be Wire-ORd, unlike the totem-pole output of the W65C22S (some customers have had to use a diode in series with the IRQB output when using the W65C22S in their systems that had Wire-ORd interrupts).


so the W65c22n is the one you want. It should not have any issues as I personally use these in mine!

:wink: Correct!

The W65C22N is from the Western Design Center and sold through Mouser.
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Kakemoms
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Re: VIC 1112 IEEE Interface

Postby Kakemoms » Mon Nov 28, 2016 9:29 am

S**t..

Unfortunately I was too quick on the buy-button on ebay.. Can I fix it with a diode on the IRQ pin?

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Kakemoms
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Re: VIC 1112 IEEE Interface

Postby Kakemoms » Wed Nov 30, 2016 3:34 pm

Kakemoms wrote:S**t..

Unfortunately I was too quick on the buy-button on ebay.. Can I fix it with a diode on the IRQ pin?


Well I found some info here that indicates that the problem is when the IRQ is put to Vcc externally while its driven internally to GND. I think that a 10k resistor (pullup) should fix that with the above mentioned diode?

dragos
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Re: VIC 1112 IEEE Interface

Postby dragos » Wed Nov 30, 2016 10:57 pm

Unfortunately I do not know the answer to this :(
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Kakemoms
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Re: VIC 1112 IEEE Interface

Postby Kakemoms » Tue Dec 06, 2016 1:46 pm

Well, we'll find out! I can check the R6522 in one of the Vic-20 I have with sockets.

Eventually I managed to get hold of an original Vic-1112 and got it up running with a 2040 (that I have managed to get running again). I can load floppy content and programs (but no Basic 4 on that one!).

So I went back to the 1112 replica and it loaded the directory once. Well, at least it told me it did, but then there was nothing in the memory. So that confirms that one (or both) the 6522 are failing. Hopefully I can test out the R6522 (with mod) before xmas.

I also have a B700 I am tinkering with, and if you look at the number of diodes+resistors on that PCB... well, they didn't take any risk on that one.

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Re: VIC 1112 IEEE Interface

Postby eslapion » Thu Dec 15, 2016 1:47 pm

Kakemoms wrote:Well I found some info here that indicates that the problem is when the IRQ is put to Vcc externally while its driven internally to GND. I think that a 10k resistor (pullup) should fix that with the above mentioned diode?

It's the opposite.

The MOS6522 IRQB can only drive low or do nothing at all. The 65C22 or R65C22 can drive low or high. This way you can connect more than one 6522 to the same IRQ line and this is done in many pieces of equipment. If a 6522 pulls low and a R65C22 pulls high then you have a tug of war between the two.

A diode may do the job but it has to be extremely fast and have a very low voltage drop. The 1N6263 I use on the Behr-Bonz DRL 'AND' gate should to the job.

A 10kOhms pull-up resistor will definitely not.
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Re: VIC 1112 IEEE Interface

Postby eslapion » Sat Dec 17, 2016 1:14 pm

To avoid the same error to other people, the good part number is: W65C22N6TPG-14

Which you can buy here: http://www.mouser.com/
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