Replica SOFTY 2

[factory]

I did buy some old Motorola branded SN74LS73AN from a UK supplier*, along with a selection of other flip-flop ICs that I didn't have in stock (some from RS/Farnell, some old stock), for experimenting to get the replacement board for a custom counter IC working, the finished design used a 74HCT107 for reasons I can't remember now.

*At least with buying in the UK you can claim a refund for defective/fake parts.

David

[ortek_service]

Originally Posted by SiriusHardware

I have to admit that's why I initially sought an SC/MP II for my MK14E from among the group here, as I had absolutely no faith that one coming from anywhere else would be 'real'.

(The one kindly supplied by Realtime is working well, I'm glad to say).

Well the first INS8060 SC/MP-II I bought was from China a few years ago when they were 'only' around £15. And I only bought one, as I thought I'd check they worked OK first, as that seemed quite expensive back then.

But in the meantime they unfortunately shot up to around £40, so no longer worth gambling when there is an established quite well-known UK online marketplace etc. seller who generally seems OK, when Chris used them in the past.
And the one I've just got from there (managing to get it for less than ones from China, and with free 24hr delivery) works OK. So I'm quite happy to try them again for these.

[ortek_service]

Originally Posted by factory

I'm really not surprized at the fake 74LS73, it's just about still made, brand new LS series are a few £ each from Farnell/Mouser, HC series are below £1, hence the relabelled HC ICs.

As far as I know, the HCT just has compatible voltage levels with LS, I've been using these in SMT form to construct replacements for custom HP ICs from the late 60s.
>>
David

Yes, I had looked at those distributors and was quite surprised how much they were for a fairly basic function logic IC.
Hence why I thought I'd try getting 10off for around the same price, as I hadn't really had any trouble before with other IC's I got cheap / didn't think they'd go to that much effort in re-marking 74HC? ones.

74HCT 'LS-Compatible' ones would have been OK (and probably also 74HC, that these fakes seem to be), if Dataman had tied the unused inputs high rather than relying on 74(LS) inputs floating-high - which may be regarded as bad practice (as is apparently tie-ing direct to supply, and not using a pull-up resistor?)

Originally Posted by factory

>>
>>
And you confirmed what I thought about the logic IC test function of the Dataman, just a basic check as the various Sunshine/Hi-Lo/Expro branded programmers, to properly check at the various voltage levels would require more complex circuitry, probably a DAC & ADC input/output to properly measure each pin. Or testing by hand.

David

Well in theory the hardware, with ability to tri-state any of the pins on the DIL48 ZIF socket, should be able to leave various inputs floating and check for correct operation. But I'm not sure whether the Test Vectors it uses allow you to specify this, as I've not really looked into these yet.
But, for TTL 'inputs' you maybe actually need a way of measuring the current they source when pulling them low to fully-check these. And I think the programmers usually only have an excess-current trip on sourcing current into pins.

Originally Posted by factory

I did buy some old Motorola branded SN74LS73AN from a UK supplier*, along with a selection of other flip-flop ICs that I didn't have in stock (some from RS/Farnell, some old stock), for experimenting to get the replacement board for a custom counter IC working, the finished design used a 74HCT107 for reasons I can't remember now.

*At least with buying in the UK you can claim a refund for defective/fake parts.

David

Well I shall try requesting replacements / a refund, for the 3off faulty 7445's / these fake 74LS73's. I have previously got a refund via Aliexpress for things not arriving / something that arrived damaged (although the seller was trying to avoid refunding the full cost, until I got Aliexpress to resolve it).
And Chris has also got refunds on faulty IC eBay purchases from China, quite often.
The most trouble I ever had was actually with a dodgy UK supplier (I should have scrolled down and read bad reviews first on them supplying parts that were wrong size / didn't fit what they were claiming) on Amazon Marketplace, where it seems there's no 'Paypal guarantee' and you're on your own to try and get a refund!

[factory]

Every new 74LS series IC I've looked at from reputable suppliers, is around £2 a part for 1 piece, as they are no longer popular (newer equipment will use the 74HC series etc) parts, fewer will be made and the costs to make them go up.

Can't say I've bought anything via Amazon for many years, this is due to their awful time-wasting search system, that provides almost everything except the item you typed in.

Another option for buying direct from China is LCSC, a major component distributor in China, they seem to have a much better reputation on the eevblog forums from people that have used them, I haven't used them myself, so don't know what delivery/fee charges they have. I tend to stick with Mouser, RS or Farnell if it's still made.

They have the usual TI parts and a cheaper option.
https://www.lcsc.com/search?q=74ls73

David

[Realtime]

I finally got around to finishing the SOFTY2 PCB build and all is looking good. I haven’t programmed an EPROM yet as I’m waiting for them to arrive, but the 50ms pulse and 25V supply look good. Next job is to get the case fitted.


If any one is building a SOFTY2 and needs a keyboard frame and overlay, PM me and we can sort it out.

[ortek_service]

Originally Posted by Realtime

I finally got around to finishing the SOFTY2 PCB build and all is looking good. I haven’t programmed an EPROM yet as I’m waiting for them to arrive, but the 50ms pulse and 25V supply look good. Next job is to get the case fitted.
Attachment 293079

If any one is building a SOFTY2 and needs a keyboard frame and overlay, PM me and we can sort it out.

Good to see another one going.

My recent build of Chris's replica PCB is nearly-complete, seemingly working for non-programming at least as mine still needs the XP-Power IHL0205D15 +/-15V DC-DC step-up module that I found Digikey were cheapest for (but I then discovered they also sell a Mornsun E0515S-2WR3 which appears to be functionally and pin-compatible but at nearly 1/3 of the price. So Chris added some of these for me to a Digikey order he was doing & now has received. So I should get next week).

Although the old small 4"? B&W monitor I've been using to test it with, didn't give quite as nice display as you've managed on your monitor (which maybe has vertical shift controls, the monitor I was using had lacked - even internally, where I'd adjusted height and width etc for best results giving the 2 extra lines of a bit random addresses? above & below that is pictured in the original manual's screenshot)

I had sent a PM to you about a frame & overlay for this (and also the original Softy-1) recently - but I'd used option to send you an email, so this may have got mis-identified as Spam?

[Realtime]

Originally Posted by ortek_service

I had sent a PM to you about a frame & overlay for this (and also the original Softy-1) recently - but I'd used option to send you an email, so this may have got mis-identified as Spam?

Sorry, I haven't received anything and nothing in Junk/spam. I'll be doing some 3D printing tomorrow so will PM you in due course.

[SiriusHardware]

I'd be interested to witness one of these being used in its 'other' mode, as an EPROM emulator. With a suitable pin-rearranging adaptor you could use it to write custom OS / monitors for old systems which insisted on having their OS in awkward ROMs (MK14, etc).

[ortek_service]

Originally Posted by Realtime

Sorry, I haven't received anything and nothing in Junk/spam. I'll be doing some 3D printing tomorrow so will PM you in due course.

Thanks. I have also tried again the 'Sending via email' - Although it doesn't seem to retain a copy of what was sent in 'Sent' via that method, but it had cached a copy of the subject so it seems it had actually sent something.
As well as copying this text to a conventional PM, in case that doesn't work (maybe email address held by forum's details is no longer current?)

[ortek_service]

Originally Posted by SiriusHardware

I'd be interested to witness one of these being used in its 'other' mode, as an EPROM emulator. With a suitable pin-rearranging adaptor you could use it to write custom OS / monitors for old systems which insisted on having their OS in awkward ROMs (MK14, etc).

Well looking at the (Chris's much-clearer, re-drawn in CAD) schematic, it looks like it should be able to substitute a 2732 (or 2532, via a link) (EP)ROM, and hopefully the dual-row header pinout enables a straight IDC cable to a 24way DIL Socket header (like with S3 & S4 where Dataman still sell the replacement cables, that I think those came supplied with).
So my have to give mine a try, once I've worked out copying of code from an EPROM into it etc, for use in a target (maybe an MK14 with ROM/RAM SC-MP adaptor, to a more conventional 2764 etc that's not too different - but still needs a few pin swaps)
Whereas it seems the Softy-1's main 'Expansion bus' was designed to allow the S1's to replace a (SC/MP?) CPU in a system, and run the code on the S1.

The S2's Tri-state buffers are all uni-directional, so it can only read the current (EP)ROM addresses and respond by writing data out of it, so it won't emulate any self-modifying code in an EEPROM / RAM area.

I've heard that the S4 would allow you to change the contents of the emulated memory, with the target still running - eg on Vehicle ECU's !
So not sure if that had dual-port RAM, rather than the conventional approach of disabling target-side buffers to conventional RAM, whilst the Emulator's uP accesses it.

[ortek_service]

Originally Posted by factory

Every new 74LS series IC I've looked at from reputable suppliers, is around £2 a part for 1 piece, as they are no longer popular (newer equipment will use the 74HC series etc) parts, fewer will be made and the costs to make them go up.
>>
Another option for buying direct from China is LCSC, a major component distributor in China, they seem to have a much better reputation on the eevblog forums from people that have used them, I haven't used them myself, so don't know what delivery/fee charges they have. I tend to stick with Mouser, RS or Farnell if it's still made.

They have the usual TI parts and a cheaper option.
https://www.lcsc.com/search?q=74ls73

David

I didn't think LS logic was generally quite that much yet - I've just looked on Farnell, and the cheapest 74LS IC's in DIL are an SN74LS74 for 46p+VAT, then SN74LS02 for 51p+VAT at 1-9off. With not that much cheaper prices for 1000+ or 74HC(T) versions. Although I'd have expected the simplest 74LS00 etc to be the cheapest.

Even 74HC(T) is maybe now getting a bit 'vintage', with move to 3.3V / down to 1.8V logic supplies and faster-speeds in more-modern equipment, so 74LVC is more-commonly used. Although at work I've also recently used 74VHC(T) / 74AHC single-gate devices, where I wanted them to be 5V tolerant and their min. 2.0V supply voltage was OK. But behaviour with voltages on inputs (and outputs), when powered-off can vary across makes as to whether they have 'Ioff' support.

Luckily, I've got a a fairly-comprehensive collection of most 74 logic IC's types, so I don't often need to buy any - only really the more obscure ones.
And would normally prefer to get more than one, to have some spares for future use.

Chris often used to use Rockby (in Australia!) for LS logic, when they were seemingly the last stockist of 8154's so ordering anyway. But I've recently found TVsat (In Poland) direct (rather than eBay) offered some very-good prices for certain types like SN74S08, SN8438 and Tesla MH7442's where you could have (usually their MOQ of) a tube worked-out at around 10p per IC.
But they did sell 74LS132's at 23p for 2off / 74LS138's at 76p for 3off
And these all seem to be genuine NOS ones, working OK so far.

It used to be a good sign if all supplied devices had the same batch-codes (Many years ago at work, we had mixed batches with tubes via a sourcing company. With many faulty ones, and X-rays revealed missing bond wires or even dies, with other serial EEPROM's having random memory location failures, so think someone had raided the factory reject bins for those!)

Whereas, these days, when I get a mixture of date/batch codes on devices from China etc, it gives a bit more confidence they haven't re-marked these.
I have v.recently got rather-cheap some GAL16V8's and Ramtron FM1608/1808 FRAM's, and whilst they were used ones (as I was able to readout their contents), they all erased OK. So it does very-much depend on who you use from China ('Lake Store' on Aliexpress seems OK so far).

But I may take a look at LCSC (I think I've discovered them before, but maybe had significant MOQ's / MOV's)

[factory]

Guess I've been searching for & buying the less popular parts, that fewer people use these days, the more common stuff I do have some old stock bought from work.

David

[ortek_service]

Originally Posted by factory

Guess I've been searching for & buying the less popular parts, that fewer people use these days, the more common stuff I do have some old stock bought from work.

David

Yes, the less-common ones are normally the ones I haven't already got (although can run out of some popular ones like LS138's and LS157's etc. if using these quite a bit and only have 74HC-versions / no 74HCT 'substitutes') and do tend to be the most expensive. Which is why I normally 'risk' buying a quantity from China etc and these have generally been OK most of the time.

Originally Posted by ortek_service

>>
>>
>>

Well I shall try requesting replacements / a refund, for the 3off faulty 7445's / these fake 74LS73's. I have previously got a refund via Aliexpress for things not arriving / something that arrived damaged (although the seller was trying to avoid refunding the full cost, until I got Aliexpress to resolve it).
And Chris has also got refunds on faulty IC eBay purchases from China, quite often.
>>

I went to my Alkiexpress orders for these earlier, and I couldn't easily find a 'contact seller' option, so just clicked on 'Refunds / Returns', and selected options that what I received was defective. I entered some (optional?) text to describe the issue, but it did also insist on attaching a photo to show the fault.

I thought it a bit much to try and show DVM / 'scope display connected to certain pins, so I just took a picture of the 'fake 74LS73's IC's on top of the original packaging and submitted that.
And I was very-pleasantly surprised to get an instant 'As a loyal customer, you have been fully-refunded' message for the total £3.07 cost (inc delivery) of these / also got an email from PayPal saying this had been refunded
With it stating 'no need to return these' (which would no doubt have cost rather more to return to there, unless you can use the marked UK distribution centre next to an airport 'returns address' that most of these now seem to come from).

So I did the same for the 7445's, explaining that 3off of the 9off were faulty / taking a photo of those with Faulty written next to them. And again, I got an instant full-refund of £7.81 for total inc. delivery I'd paid for these.
- I would have been happy just for seller to have sent some replacements for the faulty ones, but can't complain at Aliexpress giving a full-refund!

[ortek_service]

Originally Posted by SiriusHardware

To be honest I haven't noticed, but I will check that out this evening in the interests of science. I have two DOS based programmers, my Hi-Lo systems All07A and an ICE-Tech MM1000E, both of which do have that capability. However, it would be a good idea to find out if the Mempro does it too because it would be a lot more convenient to have it on a programmer whose software runs under current versions of Windows.

If not, it would be one more incentive to pay for the outrageously expensive plug-in dongle which 'converts' the Mempro to a 40Pro.

Originally Posted by factory

Having used an older Sunshine variant of the Hi-Lo with Expro software at work, I wasn't that impressed by the IC test function, it can only really tell you the pinout & basic function is OK, it can't tell the difference between output types.
If you have a pin compatible relabelled fake it will pass them too. Hopefully the Dataman will do better.
>>

David

Originally Posted by factory

>>
>>
And you confirmed what I thought about the logic IC test function of the Dataman, just a basic check as the various Sunshine/Hi-Lo/Expro branded programmers, to properly check at the various voltage levels would require more complex circuitry, probably a DAC & ADC input/output to properly measure each pin. Or testing by hand.

David

I did discover yesterday with the Dataman (48)Pro(+), that it did natively support many versions of 2532, when I entered that and narrowed down category to just EPROM's. So saves having to make pinout adaptors etc.

Whilst there, I noticed it also had a category for 'Static RAM'. So I selected that and discovered that it supported some quite-vintage devices like the 2101/5101/AM91(L)01, MM2102, and AM9111 version of the 2111. (But no 2112/AM9112 or 65(X)61 - only HN-6551).

It does say it can only do a 'Test' function on these devices, with no read / write (But it does have support for some NVRAM's + Ramtron FM1608 & FM1808 FRAM's in other categories that do allow this so can be useful for backing-up those with config data from equipment).
And by default, the 'Advanced' RAM test 'Walking one' & 'Walking zero' tests are disabled, for speed on larger devices, but you can enable these for more thorough testing.

So these functions may be useful to know about, as these memory devices aren't listed under the 'IC Test by test vectors' - Only 4000 / 74-CMOS / 74-TTL 'Libraries' - plus the odd Example / Special libraries.

I presume the Dataman 'MemPro' version does allow you to select & test those 'Static RAM' category devices, without having to pay the extra to unlock it to the full version.
So maybe more convenient than having to set-up an Arduino + links to breadboard for checking those types.