Changes
clean-up
[[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]].
Quality of the playback was nice, considering the time and price. The drumkit samples were read from the suplied tapes. There were serveral tapes with different themes. Along with the Amdrum came a sequencing program. It was able possible to play 8bit sound copy the samplesto 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 D/A converter is mono and has only one channel (mixing multiple channels is to be done by software).
* The After booting, the Amdrum software uses first sets port FFxxh[FF80h]=80h. The playback routine also scans the keyboard. The lower 8Emulators can use that feature to detect Amdrum software -bits of and, after [FF80h]=80h was detected, map the I/O port come from the last value whole range of the C register used ports FF00h..FFFFh to scan the keyboardAmdrum. Partial dissassembly of player:exx ld a* During operation,the Amdrum software uses port FFxxh. Where "xx" is garbage coming from the Amdrums keyboard scanning routine (bcsee disassembly below)add a,(hl)ex de,hladd a,(hl)inc hlex de,hlinc bcadd a,80hinc hlexx out (c),ald b,0f6hin a,(c)ld c,axor 05hout (c),ald a,0f4hin a,(66h)ld (404eh),aout (c),c ld b,0ffhnop nop nop exx ld a,(bc)add a,(hl)ex de,hladd a,(hl)inc hlex de,hlinc bcadd a,80hinc hlexx out (c),a.
The five chips on the single-sided PCB are:
|74LS32N||Quad 2-input OR||Port decoding, /DAC_WRITE when /ADDR_MATCH, /IORQ, /WR all LOW
|-
|SN74LS04N||Hex Inverters||purpose unknown? (used in the analog partCharge pump circuit, not used to create negative voltage rail for Port decoding)the op amp
|-
|TL064CDP||Quad Operational Amplifier||no info how the 4 amplifier stages are used?Buffer and low pass filter
|-
|Ferranti ZN428E-8||8bit DAC||mono one-channel 8bit D/A converter (unsigned samples)
* [[Media:TL064.pdf|TL064 Datasheet]] - Quad Amplifier
== 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=== Electro Kit Covertape ==="300dpi scans by Robcfg">
Image:AMDRUM_PCB_Top.jpg|PCB TopImage:AMDRUM_PCB_Bottom.jpg|PCB BottomImage:AMDRUM_Top.jpg|Interface TopImage:AMDRUM_Bottom.jpg|Interface Bottom </gallery caption="Electro Kit Covertape - Instructions">
</gallery>
=== Latin Kit Covertape =Reviews / Commercials ==
<gallery caption="Latin Kit Covertape - InstructionsCommercials for the Amdrum">
Image:Latin Kit 1amdrum commercial.jpg|Latin Kit CovertapeCommercial for AmdrumImage:Latin Kit 2Amstrad Computer User8610028.jpg|Latin Kit InstructionsReview of the Amdrum in [[Amstrad Computer User]]Image:Amstrad Computer User8610029.jpgImage:Amstrad Computer User8610030.jpg
</gallery>
<gallery caption="Amdrum Tape">
</gallery>
=== Afro Kit Tape =Kits ==
{| class="wikitable sortable" style="width:100%"|''Title''||''Front Covertape''||''Back Covertape''||''Tape Side A''||''Tape Side B''|-|[[Afro Kit]]||[[Image:Afro Kit 1.jpg|120px]]||[[Image:Afro Kit 2.jpg|120px]]||[[Image:Afro Kit Tape A.jpg|120px]]||[[Image:Afro Kit Tape side AB.jpg|120px]]|-|[[Electro Kit]]||[[Image:Afro Electro Kit 1.jpg|120px]]||[[Image:Electro Kit 2.jpg|120px]]||[[Image:Electro Kit Tape A.jpg|120px]]||[[Image:Electro Kit Tape B.jpg|Afro 120px]]|-|[[Latin Kit]]||[[Image:Latin Kit 1.jpg|120px]]||[[Image:Latin Kit 2.jpg|120px]]||[[Image:Latin Kit Tape A.jpg|120px]]||[[Image:Latin Kit Tape side B.jpg|120px]]|-|}
</gallerycaption="Afro Kit - Errata">
</gallery>
== Other playback devices ==
== Videos ==
AmDrum on Amstrad CPC (emulated with JavaCPC)
{{#ev:youtube|0z-jGDOzwGQ|400}}
A presentation(from around 1985) of the ZX Spectrum version of the Amdrum(Specdrum), also mention of the upcomming Amstrad CPC version
{{#ev:youtube|m6R_W9CZWGU|200400}} == Manual == * [[Media:Amdrum Manual.pdf|Amdrum (Cheetah) Manual]] {{EN}} {{PDF}}
== Download ==
* [[Media:Amdrum Latin Kit.zip|Amdrum Latin Kit.zip]] (CDT for Emulators)
* [[CategoryMedia:HardwareAmdrum (Eagle).zip|Amdrum (Eagle).zip]] (Amdrum files for Eagle) == Weblinks == * [http://www.cpc-power.com/index.php?page=detail&num=4294 ''Amdrum'' from CPC-Power]* [http://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:Peripherals]] [[Category:Music and sound]] [[Category:Manual]][[Category:Video contents]]
