Paul wrote:I received the working Forth Zeddy today and extracted the ROM.
It is identical with the H4TH.ROM that was supplied with EightyOne.
Both work with EightyOne without problems and I did the check with the ROM file of EO, it works perfectly in an Issue One Zeddy in Hardware.
It's a 50hz Version, not 60hz. And yes, the Video output starts quite high and to the right but works ok. It's just the way it is
No Idea who or what happend so someone thought it might not work.
Maybe the fact that at least two Kilobytes of Memory are neccessary? So no reaction with 1K.
Unless someone comes up with a even more "original" Zeddy running H4TH this must be thought of beeing the original Version that can be downloaded everywhere.
Kind regards
Paul
Yes and it works with my zeddies also.
The points that were being made were that the screen position is not so far out in eighty one but is with real zeddy also the inverse mask covers all characters in eighty one but with real zeddy the right most column is not masked try it Paul and see for your self, or look at the pictures earlier in the thread.
When stefano made a patched version of H4th it worked perfectly in eighty one with a more centred screen position etc, but when burned to an EPROM it did not work with real zeddy again see pictures earlier in thread.
My conclusion being that eighty one is not really a sound application to make SOME assumptions concerning real equipment or put another way it looks and seems to work like the real thing but not truly emulating the 81 at a base level hence the different results mentioned earlier.
I have looked at the picture of the EPROM from which you extracted the image and it is not an original skywave EPROM so unless source can be truly verified who's to say it has not been altered in some way to work with eighty one which due to the points already mentioned does operate fractionally differently on the real thing.
As I said at the beginning the only image we have is the h4th one not an original Skywave one and who's to say Mike Wynne did't patch it to work with eighty one? I'm sure I read somewhere that the Ace ROM was altered to work in eighty one. The following that accompanies eighty one is intriguing ....
"Version 0.31 11/11/04
Tidied up the Tape Manager (it's now resizable!). Fixed a bug in the interupt generation code.
This solves a problem where the display would get shifted left or right depending on the code
used to create it. H-Forth and TreeForth ROMs now work correctly (They need to be configured
in a certain way - ROM patches off, 16k of RAM and Shadow RAM on)."
There are one or two other bugs I have found along the way but as most zeddy users are not Forth enthusiasts and only have the image to complete the collection so to speak then none of this is important, at the end of the day it is just a small mind game to pass the time nothing more.
PS Paul My wife sends her regards and was glad you enjoyed the sandwiches.
Sorry for the time I made you spend on it, Moggy !