FIRMWARE / hardware IN PROGRESS -  some infos are  missing !

Please, do not buy ..

Disclaimers - READ THAT FIRST !   5 times at least !

• If you are not familiar with soldering or you do not have proper tools, please LET a pro technician do it for you or send me your ZX for installation. Upgrade installation cost is 40€ + postage. Contact me to arrange installation.
• Please remeber - wrong tools usage or low skills may damage Your Sr_ULA;
• any damage/harm to your hardware is NOT subject of any kind of warranty.
• Installation is easy, but unexperienced hands can do a lot of damage. 
• Amstrad models have ram organised other way as regular 128.. i have no idea if there is soft that works only with amstrad, but mode is present :-)
• Sr-ULA doesn`t produce YUV and will never do it. This is part of history and shall be forgotten forever...brrrrr :-)
• Sr-ULA idea and concept assumes modulator removal and installation of supplied rgb adapter with Sega Mini-DIN/9 connector compatible 

If You want to know:

• how to upgrade ZX SPECTRUM_48 
• how to repair it within few minutes ...

please, read below :-)

        Sr-Ula story reaches September 2022, when first device was made - MAMLAS_CPLD. It was simple cpld "ula" implementation i have designed to finally fix my faulty ZX Spectrum 48. Since that time, I have used heavily my zx to test video ram replacements, Bison and others devices from my offer i have been working on. One day, during very heavy judo training i got "mind bang" and final concept was born...solution of main problem - full Z80 address  presence  at ULA`s socket /of course  without extra physical connections/

Ladies, Gentlemen,

Boys and Girls,

I am very happy to introduce  "Sr-ULA" 

Technical info:

• mounted in the place of ULA chip in ZX Spectrum
• 512KB of sram / bga, bottom momunted/ - SNOW effect no more ;-) as Z80 RFSH not used
• FPGA based / Gw1n tqfp 
• 4layers, 24 x 52 mm, double sided
• 2 customs clocks osc  : 28Mhz and 28, 37516 MHz to get PERFECT timings in diffrent modes. 
• 8 modes controlled by avr and stored after power off  (BUTTON connector -  short press - mode change, long press - reset) :
  • ZX48
  • ZX128
  • Penatgon
  • Amstrad models
  • soon timex.... work in progress 
• Turbosund (2 x AY 3-8912 chips)
• ULAplus
• Mono covox (Pentagon ans SpecDrum standards)
• SounDrive (4-channel stereo covox) ..
• RAM - 128K available via 7FFDh and 384K via DFFDh /Sizif`s style/

MODES:

INSTALLATION STEP BY STEP: 

Befor You start, You need:

• soldering iron
• desoldering punp
• 1 x 10k resistor 
• 1 short wire - 5cm
• calm hands (old bourbon 100ml suggested)

• replace orginal with SRULA ( WARNING - PIN 1 is marked with white triangle)
• i suggest at first step to use socket...for tests. after tests, i suggest soldering SRULA into zx board directly.
• 3 wire connections shall be made to CPU:  M1,RESET,IORQ 
• disable CPU ram - connect only once CAS to 5V via 10k resistor (not supplied) or best - REMOVE IT
• CAS signal is present at pin 15 of  every memory chip (8 pieces at motherboard under CPU Z80)

• ULA`s ram is beig disabled by Sr_ULA, You can remove it forever... or remove it if You can feel them hot
• Ready! SR_ULA installed  (time for bourbon)
• Remove modulator 
• Install RGB adapter - do not forget about 5V supply  - Soon video....
• connect pcbs with supplied zif cable ( bottom contacts)
• If You have done everything properly and following requirments are met:
  • Your cable is properly made - diagram below
  • Your Z80 / ROM is OK
  • ULA address multipelexers are ok , after power on You will see zx specrum screen

VIDEO CABLE DIAGRAM:

/some chinese sega cables have resistors and capacitor on RGB LINES - remove !/

ONLY DIRECT CONNETIONS ! no electronics between pins of scart and mini din. 

ps. below picture shows +5v - ignore value, it is blanking signal. 

Real hardware video: Sr_ULA + MEDUSA + Bizon

Inside BOX:

• Super_ULA module
• rgb adapter 
• flat zif cable 

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