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[[Image:Amdrum.JPG|thumb|250px|Box and Manual for the Amdrum]]
The Amdrum is an 8bit D/A converter (hardware) with drumkit (software), made by the British company [[Cheetah]].The drumkit was able to play 8bit sound samples.Quality of the playback was nice, considering the time and price.The samples was read from the suplied tapes.There was serveral tapes with different themes!Along with the Amdrum came a sequencing program.It was possible to copy the samples to disc, but the sequencing program had to be patched!
Quality of the playback was nice, considering the time and price. The samples were read from the suplied tapes. There were serveral tapes with different themes. Along with the Amdrum came a sequencing program. It was possible to copy the samples to disc, but the sequencing program had to be patched! Amdrum was probably Cheetahs version of the SpecDrum (As revealed on the PCB "AMSTRAD SPECDRUM"). Aside of Cheetahs own sequencer you can use some commands of the RSX ROM for [[LambdaSpeak III ROM|LambdaSpeak III]] to use the Amdrum.
== Technical Specifications ==
* Uses I/O Port FFxxh (Write only), ie. only /IORQ, /WR, A15-A8 are decoded. A7..A0 are not decoded, and /RD isn't used, too.* Port usage: Write 8bit unsigned sample data to Port FFxxh. The PCBD/A converter is mono and has only one channel (onesidemixing multiple channels is to be done by software) contains .* After booting, the Amdrum software first sets port [FF80h]=80h. Emulators can use that feature to detect Amdrum software - and, after [FF80h]=80h was detected, map the whole range of ports FF00h..FFFFh to the Amdrum.* During operation, the Amdrum software uses port FFxxh. Where "xx" is garbage coming from the Amdrums keyboard scanning routine (see disassembly below). The five chipson the single-sided PCB are:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|74LS30N||Single 8-input NAND||Port decoding , /ADDR_MATCH=LOW when A8..A15 all HIGH
|-
|74LS32N||Quad 2-input OR||Port decoding, /DAC_WRITE when /ADDR_MATCH, /IORQ, /WR all LOW
|-
|SN74LS04N||?Hex Inverters||Charge pump circuit, used to create negative voltage rail for the op amp
|-
|064C0PTL064CDP||Quad Operational Amplifier?||Buffer and low pass filter
|-
|Ferranti ZN428E-8||8bit DAC||mono one-channel 8bit D/A converter (unsigned samples)
|}
== Kits Partial dissassembly of player == exx ld a,(bc) ;get channel 1 add a,(hl) ;add channel 2 ex de,hl add a,(hl) ;add channel 3 inc hl ex de,hl inc bc add a,80h ;add bias (signed to unsigned) inc hl exx out (c),a ;out [FFxxh] with C=whatever ld b,0f6h in a,(c) ld c,a ;C=PIO Port C (keyb row, tape, psg control) xor 05h ;five ??? out (c),a ld a,0f4h in a,(66h) ld (404eh),a out (c),c ... ;something missing here? ld b,0ffh nop nop nop exx ld a,(bc) ;get channel 1 add a,(hl) ;add channel 2 ex de,hl add a,(hl) ;add channel 3 inc hl ex de,hl inc bc add a,80h ;add bias (signed to unsigned) inc hl exx out (c),a ;out [FFxxh] with xx=garbage (above PIO Port C value)
=== Afro Kit Covertape =Pictures ==
<gallery caption="Afro Kit Covertape - InstructionsAMDRUM">
Image:Afro Kit 1Amdrum_1.jpg|Afro Kit CovertapeBoxImage:Afro Kit 2Amdrum_2.jpg|Afro Kit InstructionsAmdrum inside boxImage:Afro Kit ErrataAmdrum screen shot 1.jpggif|Screen shotImage:Amdrum screen shot 2.gif|Afro Kit ErrataScreen shot
</gallery>
<gallery caption== Tapes =="300dpi scans by Robcfg">
</gallery caption="Amdrum Tape">
</gallery>
=== Afro Kit Tape =Reviews / Commercials ==
<gallery caption="Afro Kit TapeCommercials for the Amdrum">
Image:Afro Kit Tape Aamdrum commercial.jpg|Afro Kit Tape side ACommercial for AmdrumImage:Afro Kit Tape BAmstrad Computer User8610028.jpg|Afro Kit Tape side BReview of the Amdrum in [[Amstrad Computer User]]Image:Amstrad Computer User8610029.jpgImage:Amstrad Computer User8610030.jpg
</gallery>
=== Electro Kit Amdrum Tape ===
<gallery caption="Electro Kit Amdrum Tape">
Image:Electro Kit Amdrum Tape A.jpg|Electro Kit Amdrum Tape side AImage:Electro Kit Amdrum Tape B.jpg|Electro Kit Amdrum Tape side B
</gallery>
=== Latin Kit Tape =Kits ==
{| class="wikitable sortable" style="width:100%"|''Title''||''Front Covertape''||''Back Covertape''||''Tape Side A''||''Tape Side B''|-|[[Afro Kit]]||[[Image:Latin Afro Kit 1.jpg|120px]]||[[Image:Afro Kit 2.jpg|120px]]||[[Image:Afro Kit Tape A.jpg|Latin 120px]]||[[Image:Afro Kit Tape B.jpg|120px]]|-|[[Electro Kit]]||[[Image:Electro Kit 1.jpg|120px]]||[[Image:Electro Kit 2.jpg|120px]]||[[Image:Electro Kit Tape side A.jpg|120px]]||[[Image:Electro Kit Tape B.jpg|120px]]|-|[[Latin Kit]]||[[Image:Latin Kit 1.jpg|120px]]||[[Image:Latin Kit 2.jpg|120px]]||[[Image:Latin Kit Tape BA.jpg|120px]]||[[Image:Latin Kit Tape side B.jpg|120px]]|-|} <gallery caption="Afro Kit - Errata"> Image:Afro Kit Errata.jpg|Afro Kit Errata
</gallery>
== Pictures Other playback devices ==
* [http[Media://wwwAmdrum Manual.crashonline.org.uk/27/specdrum.htm Review of the Spectrum versionpdf|Amdrum (Cheetah) Manual]]{{EN}} {{PDF}}
* [http://www.cpc-power.com/index.php?page=detail&num=4294 ''Amdrum'' from CPC-Power]* [Digiblasterhttp://www.cpc-power.com/index.php?page=detail&num=4312 ''Amdrum Afro kit'' from CPC-Power]* [http://www.cpc-power.com/index.php?page=detail&num=4313 ''Amdrum Electro kit'' from CPC-Power]* [http://www.cpc-power.com/index.php?page=detail&num=4311 ''Amdrum Latin kit'' from CPC-Power]* [https://cpcrulez.fr/hardware-audio-amdrum_AA.htm ''Amdrum'' from CPCrulez]* [http://hardware.speccy.org/temp/Amstrad-Amdrum.html ''Amdrum'' from hardware.speccy.org]* [http://www.engadget.com/2005/10/28/music-thing-the-zx-spectrum-specdrum-module/ Site about the SpecDrum]* [http://www.crashonline.org.uk/27/specdrum.htm Review of the Spectrum version]* [http://www.worldofspectrum.org/hardware/feat42.html Another Spectrum review]
[[Category:HardwarePeripherals]] [[Category:PeripheralsMusic and sound]] [[Category:Music and soundManual]] [[Category:ManualVideo contents]]
