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One thing I have tried in the past is to wire the inputs and control signals to a second IC on a breadboard and compare the outputs. If I see the good chip changing faster / differently, then it's time to warm up the desoldering station.

I have seen 244s and 245s where the outputs got a bit sloppy. Sometimes they didn't change very fast, sometimes they didn't change at all. The 240 is probably very similar and may be susceptible to the same thing. Can remove any of the loading on it to see if that is dragging it down?

D0, sorry D0 not A0.

Yes, the arrays look right, I couldn't see clearly in the previous photo. Looking at the screen, ZW80 BBSJC suggests you have a problem on the A0 line, a short somewhere? (X=$61, but you see W=$60, A=$38, but you see B $39)

Check the resistor arrays by the 245. The dot on the package should match the dot on the PCB. Looks like you have switches 1,4,7 and 9 on? That's not a valid combination. Try 3 and 7 on, all the rest off. I changed to using DIP switches to make it easier. I guess that didn't work. Oh well .....

X marks the ones you should turn on. Start with 1 and 3 for Jupiter Ace, or 3 and 7 for ZX81.

Check the manual, it looks like you don't have any of the DIP switches on, so there will be no clock.

Sadly it seems to be heading in that increasingly parochial direction. Some people want the US to be only able to buy from the US, and others are making it increasingly difficult to get things in and out of Europe. I still ship worldwide if you email me, but I have had to set my stores to UK only.

That is the way I am having to doing it now. What I need is for it to be automatically calculated on the marketplace e.g. Tindie so the buyer is told the full cost of shipping and duties etc. and pays that up front. Until that happens, I am stuck with manual invoicing.

At least someone finds it useful, but please tell me the secret. How to you automatically calculate the various duties and fees in advance to get the buyer to pay those?

Please come back next week when there is a nice post about writing a VIC 20 game. Or there is 50% of my Patreon if you want to read it now, along with many hundreds of other posts. www.patreon.com/tynemouthsof... I don't normally mention Patreon, but I could really do with the support right now.

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Two problem, the higher the price, the fewer the sales. Second if I make the £100 product £120 to cover the duty, then the paperwork is wrong because it then wants duty on a £120 item. Tindie has no support for collecting tariffs or duties or anything like that to cover it.

For example, I have a £200 order that I now cannot ship without paying £40 duty as well as £25 postage and handling fees etc. How am I supposed to get the buyer to give me £40 so I can pay it to the Post Office in order to post the item?

The €3 per type of item I was absorbing in the postage costs, I can just about cope with that. In the past (last month) I sent items and the buyer paid duty. The problem is Germany, and some other countries, now do not have that option. I have to pay 20% of the value + handling fee with the postage.

Why is it now my job to collect duty on items I am sending abroad? I can't put my prices up 20% to cover it, as the paperwork would be wrong. Add it to the postage? Maybe, but it then looks ridiculously expensive. It's no wonder no one is buying anything and the sellers are all giving up.

Thank you. The board was courtesy of @markgbeckett.bsky.social and worked perfectly, thanks for sharing that. The pins on the sockets I had were too big, but the 9V worked well enough on a ZX Printer that just line feeds. All of mine are broken in one way or another so I only tested the Alphacom 32.

CATALOG / DIRECTORY was my torture test when I was developing the SD2PET. Constantly stopping and starting, 2-3 bytes at a time, stopping you just as you get ready to send the next byte. I did work on an IEEE to IEC adapter, but could never get the CAT/DIR stop/start to work reliably every time.

I have looked into adding it a few times, but it requires extra hardware to disable the ROM and switch in RAM at $0000, and some form of disk storage or large bankable ROM. When I tried it out, it was a bit limited with 32 character screen width.

As well as Jupiter Ace Forth, the Minstrel 4th can also run * Enhanced Ace Forth with support for serial comms * ZX80 BASIC * ZX81 BASIC * Lambda 8300 BASIC * ZX-Forth * Microprossor MPF-I and I am sure more to follow github.com/tynemouthsof... www.tindie.com/products/tyn...

I think this is the relevant section. If block count > 10, decrease padding. If > 100, decrease padding again.