FreeLists / zxspectrum / [zxspectrum] Fw: Regular ZX128 & PENTAGON?

["Stefano" <flydream@xxxxxxxx>]

E' una notizia che già sapevo (infatti l'ho messa 2 settimane fa sul mio
sito). Ecco le specifiche della scheda che rende compatibili gli Spectrum
originali con  Pentagon e Profi :-)

----- Original Message ----- 
From: "Mr Y" <yerzmyey@xxxxxxxxxxxxxx>
To: <yerzmyey@xxxxxxxxxx>
Sent: Wednesday, June 09, 2004 6:08 PM
Subject: Regular ZX128 & PENTAGON?


> Probably most of You know it already, but have new work now and... You
> know. Time.
> It's from Xagon's board.
> It is about new interface for Speccy - it make Your comp compatible with
> Pentagon (and not only) and also it gives You up to 1024Kb of RAM.
>
> _________________________________________
> Hi, I just translate Velesoft's message from Pandora.cz.
> VELESOFT wrote:
> --------------------- 
> Finally, I have finished the final concept of an internal
> interface for ZX128+2. Till now I have been testing only the
> first prototype. Two days non-stop (I didn't sleep) - I designed
> patterns to program GAL circuits.
> The original version expands the ZXS 128 memory to 512kB,
> includes 512kB EPROM (32kB ROMs are selectable using manual
> switch), it allows to speed up all 128k pages (ULA doesn't slow down
> them).
> The new version is built on the original prototype.
> Hardware modifications are almost not needed.
> On the PCB are three GAL ICs connected together.
> I programmed completely all of them and used some
> of their other pins.
> I'm only testing the whole thing step by step but I
> believe it will run at the first try, like the previous
> version.
>
> I have added the following things to the GALs:
>
> - addressing up to 1MB SRAM
>
> - integrated UMBRELLA (anti-snower for videoram)
>
> - ZX 128+2 mode (without changes)
>
> - Pentagon 512kB mode (all memory is fast)
> Higher RAM uses addressing via bits 6 and 7 of port 7FFD.
> ALLRAM mode possibility (see below)
>
> - Pentagon 1024kB mode (slow and fast pages like ZX128)
> Higher RAM switches pages via bits 5,6 and 7 on port 7FFD.
> Intersting thing is that bit 5 is also used for page switching,
> on which is blocking of page switching on normal ZX.
> This is not possible here, but it can select up to 1MB RAM.
> ALLRAM mode possibility (see below)
>
> - at the end the best , ZX PROFI 1024kB mode.
> (everywhere fast ram)
> Page switch via 7FFD, like on ZX128.
> Higher ram switches via bits 1,2 and 3 on port DFFD!
> Port 23 not accessible (ALLRAM).
> But allram and mode is possible to set up also via port DFFD.
> Port DFFD is available only in this mode !
>
> - you can activate D40/D80 modification in all modes.
> (sets 48k ROM)
>
> - in ZX128+2 or Pentagon 512kB modes there is possibility
> to turn on ALLRAM mode via port 23. Bits 0,1 and 2 of the
> part 23 say, which number of RAM page should be connected
> instead of ROM into the low 16kB area.
> I did what I could, so the ALLRAM mode is at least compatible
> with MB02. Sadly, for ALLRAM is possible to use only the
> 128kB SRAM (8 memory pages which are in the higher
> memory area above 128kB RAM)
>
> - a difference is in ZX PROFI 1024 and Pentagon 1024 modes,
> where only the page 8 is set for ALLRAM. (above ZX128 RAM)
>
> - on the part 23 is, of course, also a WRITE PROTECT for
> ALLRAM and two bits for working mode change.
>
> - instead of ROM there will be EPROM 128kB (of FLASH EPROM)
> and an extra ROM (32kB) will be set for all of the 4 modes.
>
> The whole modification is on a PCB of cca. 7 x 7 cm
> and is pluggable right into the ZX ROM (and HAL) socket.
> The extended memory is of course not erased after reset and
> I think about battery backup of the complete 512kB/1MB SRAM.
> Then I simply turn on the Speccy again and go on.
>
>
> There exist a new version of MFC (filemanager for D80 -note Fcr6)
> which can copy whole D40/D80 disk with only one disk change.
> MFC automatically detects the type of computer 48/128 and
> the user manually sets working range of work memory.
> MFC is using page switching only via &FFD and uses higher
> bits of the port (7,6 and 5).
>
> Also, there exist several versions of TRDOS for ZX PROFI 1024kB.
> These TRDOSes can work with ramdisk. You can only load
> complete image (.TRD) into memory and swith on TRDOS.
> DivIDE could map TRDOS. Someone could write a routine
> which loads .TRD file from CD or compact flash card into
> the RAM of ZX PROFI.
>
> VELESOFT
> (stupid translation by Factor6 - kill me)
> _________________________________________
>
> And more text about its price (this time from +Gama):
>
> _______________________
> >>Board itself (double-sided, hand-drilled non-coppered holes) is
something less
> than 10 euro, 3x
> GAL, "I'm shitting" chips and sockets about next 10 euro, so it
> should remain about 20 euro
> (without postage) in the EASY version.
> The BIG version with more possibilities will follow soon.
> You can ask him for details at e-mail sprinter2000(NOSPAM)quick.cz <<
> _______________________
>
> Regards,
>       Yerz
>