New (and compact) ZVC design.

[Sylvain Cote]

Hello Diego,

This is great news !!!

Do you need ZEPROM's for your testing? I have plenty.

This new device needs a name ...

DVC → Diego Voltage Converter ?
ZVC2 → Zeprom Voltage Converter version 2 ?

Some background ...

• The ZEPROM is a 16K EPROM module for the HP-41 that was made by Zengrange.
  
• The module can be configured as
  • a flat 8K module
  • a flat 16K module
  • a banked switched 12K (4K+2x4K) [this is a banked switched 16K with a special setup]
  • a banked switched 16K (2x8K)
    
• The PROGRAMMMER ROM is normally used with the ZVC to program the ZEPROM. (The ROM was burned in each ZEPROM sold)
  
  Code:
  

  XROM   FUNCTION  DESCRIPTION
-----  --------  ---------------------------------------------------
09,01  ADDBSW    Add bank-switching code to initialised page
09,02  ADDMCF    Add M-code bank-switching functions
09,03  ADDUCF    Add user code bank-switching functions
       BGTOxx    User code bank-switching GTO
09,04  BLANK?    Test if the page in Reg X is blank
09,05  BNKSW?    Test if page in Reg X is bank-switched
       BRTNxx    User code bank-switching RTN
09,06  BURNUC    Burn user code program from RAM or ROM
09,07  BURNWD    Burn word in Reg X into address in Reg Y
       BXEQxx    User code bank-switching XEQ
09,08  CHKSUM    Compute & return checksum for specified page
09,09  COMPUC    Compile user code program in mai nmemory
09,10  COPYPG    Copy entire 4K image between pages X & Y
09,11  CPXYZ     Copy data as specified in Regs X,Y,Z
09,12  DECHEX    Convert decimal value in Reg X into hexadecimal
09,13  ENABLEP   Enable primary bank of ROM page in Reg X
09,14  ENABLES   Enable secondary bank of ROM page in Reg X
09,15  FRSPC?    Address and amount of free space of page in Reg X
09,16  HEXDEC    Convert hexadecimal string into decimal number
09,25  ILBURN    Burn page using image from IL mass storage file
09,26  ILSAVE    Save ZEPROM page image into HP-IL mass storage file
09,17  INITPG    Initialise a ZEPROM Page
09,22  PB09      Enable primary bank of Programmer ROM module
       PBxx      Enable primary bank of ROM with XROM-id of xx
09,23  PGX=Y?    Compare two 4K ROM pages for equality
09,24  PRGMLN    Return program length and number of LBLs
09,25  READWD    Read word from ROM page in RegX
09,26  REBURN    Recover from error in burning user code program
09,27  RRBURN    Burn ZENROM ROMREG + format data into ZEPROM
09,28  SB09      Enable secondary bank of Programmer ROM module
       SBxx      Enable secondary bank of ROM with XROM-id of xx
• Zeprom Programmer's Manual
• A UV light box is needed to erase the module.
  
• A Zeprom Voltage Converter (ZVC) or the new module from Diego is needed to program the module.
  
  
  
  

There are lots of programmed ZEPROM modules floating around on eBay.
Until today, the ZVC rarity and the associated asking price prevented to reused those modules.
For sure, the ZEPROM is not as powerful as the Clonix-D module, but if they can be reused why wasting them.
Thank you Diego!

Oh! and BTW, I will take three units when available. ;-)

Best regards,

Sylvain