UMBRELLA (HAL10H8 replacement) for ZX 128 / +2

Umbrella is new replacement of original HAL10H8(PAL10H8) chip used in ZX Spectrum 128 and +2(grey).
New is used chip GAL16V8 with unrainer effect and disable read port #7FFD.

New GAL in ZX128+2 (ISSUE 3)

Original HAL, PAL and new GAL16V8
Original HAL10H8 (PAL10H8) New GAL16V8


          HAL10H8 pinout
         ._____    _____.
         |     \__/     |
     A15 |  1        20 | VCC
     A14 |  2        19 | VA14
      A1 |  3        18 | VA15
    IORQ |  4        17 | ULA15
      B0 |  5        16 | ULA14
      B1 |  6        15 | UA15
      B2 |  7        14 | UA14
      RD |  8        13 | BANK
      WR |  9        12 | PSG
     GND | 10        11 | NC
         |______________|


     Pin   Signal    Type
     ---   -----     ----
     1     A15       com input
     2     A14       com input
     3     A1        com input
     4     IORQ      com input
     5     B0        com input
     6     B1        com input
     7     B2        com input
     8     RD        com input
     9     WR        com input
     10    GND       ground pin
     11    NC        unused
     12    PSG       pos,com output
     13    BANK      pos,com output
     14    UA14      pos,com output
     15    UA15      pos,com output
     16    ULA14     pos,com output
     17    ULA15     pos,com output
     18    VA15      pos,com output
     19    VA14      pos,com output
     20    VCC       power pin

;Original equations:
;bugs: raining, enable IN(#7FFD) = crash



EQUATIONS

PSG   = !WR & !A1 & !IORQ & A15  | !RD & !A1 & !IORQ & A15


BANK  = !WR & !A1 & !IORQ & !A15 | !RD & !A1 & !IORQ & !A15



ULA15 = A15 & !A14 | A15 & A14 & !B0

ULA14 = !A15 & A14 | A15 & A14 & B0

UA15  = A15 & !A14 | A15 & A14 & !B0 & B1

UA14  = A15 & A14 & !B0 & B2

VA15  = A15 & A14 & B0 & B1

VA14  = !A15 & A14 | A15 & A14 & B0 & B2

 


          GAL16V8 pinout
         ._____    _____.
         |     \__/     |
     A15 |  1        20 | VCC
     A14 |  2        19 | VA14
      A1 |  3        18 | VA15
    IORQ |  4        17 | ULA15
      B0 |  5        16 | ULA14
      B1 |  6        15 | UA15
      B2 |  7        14 | UA14
      RD |  8        13 | BANK
      WR |  9        12 | PSG
     GND | 10        11 | RFSH
         |______________|


     Pin   Signal    Type
     ---   -----     ----
     1     A15       com input
     2     A14       com input
     3     A1        com input
     4     IORQ      com input
     5     B0        com input
     6     B1        com input
     7     B2        com input
     8     RD        com input
     9     WR        com input
     10    GND       ground pin
     11    RFSH      com input
     12    PSG       pos,com output
     13    BANK      pos,com output
     14    UA14      pos,com output
     15    UA15      pos,com output
     16    ULA14     pos,com output
     17    ULA15     pos,com output
     18    VA15      pos,com output
     19    VA14      pos,com output
     20    VCC       power pin

;Modificated equations:
;Unraining, no IN(#7FFD) crash
;Created by POKE 10-08-2003.


EQUATIONS

PSG   = !WR & !A1 & !IORQ & A15  | !RD & !A1 & !IORQ & A15

; Disable read from #7FFD port!
BANK  = !WR & RD & !A1 & !IORQ & !A15

; Disable address to contended RAM in refresh cycle
;(stop raining)
ULA15 = A15 & !A14 | A15 & A14 & !B0 | !RFSH

ULA14 = !A15 & A14 | A15 & A14 & B0

UA15  = A15 & !A14 | A15 & A14 & !B0 & B1

UA14  = A15 & A14 & !B0 & B2

VA15  = A15 & A14 & B0 & B1

VA14  = !A15 & A14 | A15 & A14 & B0 & B2

 

DOWNLOAD
HAL10H8(PAL10H8) - original (with orig.bugs)
GAL16V8 (100 % CLONE - with original bugs)

DOWNLOAD
GAL16V8 (bug-fixed: anti-snowing, port #7FFD is write only)

For this new GAL16V8 you must connect pin 11 of GAL with signal RFSH (pin 28 on Z80CPU). In other GAL/HAL/PAL versions is pin 11 not used)

LINKS:

 http://www.speccy.org/trastero/cosas/JL/Pal/PAL10H8.html

My PENTAGON INTERFACE use upgraded UMBRELLA chip with more features
http://velesoft.speccy.cz/pentagon512_interface.htm