stefano wrote:Interesting. On the screen being shifted on the top-right I noticed the same effect on EO, which should be fixable.
The NTSC version does not seem to suffer the same problem, did you try it ? I don't know if there are compatibilty problem mixings the zx81 version and the h4 ROM versions.
The strange thing of a missing inverse attribute on a column is odd.. on did you test the rom on an original zx81 ?
Yes Stefano the visual faults are only apparent on real ZX81 using the ROM image from eighty one, and I have burned three EPROMS (2764 as per original)with this image to make sure it was not a one off.
The display being up and to the right is more apparent on real ZX81 and as for the missing inverse it is almost like half a character wide if you can understand what I mean the letter p used in my example shows the downstroke of the p inverted but not the loop of the p .
I should also add I only use real Zeddy(PAL) on old CRT TV as the original ROM was intended to be used so cannot try NTSC version.
How it works on emulators is of no interest to me only insofar as it effects real equipment and like I said before if no one has a genuine original EPROM from Skywave software to compare with the eighty one image then everything is guesswork.
A screen shot as example please excuse poor camera work.