Memory Mod: Difference between revisions
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'''Memory Mod''' refers to upgrading a DVB card |
'''Memory Mod''' refers to upgrading a, so called, "[[Full-featured Card|full-featured]]" DVB card equipped with 2MByte SDRAM to 4MByte of SDRAM by means of placing another memory chip over an existing chip. The idea for this modification was introduced by [http://escape-edv.de/endriss/dvb-mem-mod/index.html Oliver Endriss]. |
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==The Idea== |
==The Idea== |
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"[[Full-featured Card|Full-featured]]" DVB cards are equipped with a 2 MByte SDRAM chip. Using the Linux DVB |
"[[Full-featured Card|Full-featured]]" DVB cards are equipped with a 2 MByte SDRAM chip. Using the Linux DVB drivers, OSD memory space is limited to approx. 80 KBytes. Therefore, it is not possible to have a full-screen, 256 color OSD when using [[VDR]]. However, the onboard [[AV711x|AV7110/7111 MPEG2 Decoder]] used by these cards is able to handle/address two 2MByte SDRAM chips. Doubling the amount of addressable memory onboard these cards would effectively resolve the limitation outlined above and, hence, users could gain a full-screen 256 color OSD in VDR. Additionally there would be more space for the video buffers. Given the obvious benefit, why not add the second one? |
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==The Modification== |
==The Modification== |
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The chip select for the second SDRAM chip is not available on the pcb itself, so the |
The chip select for the second SDRAM chip is not available on the pcb itself, so the AV7110 processor and the memory chip have to be modified. |
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|[[Image:Memory_Mod_Pic1.jpg|thumb|none|AV7110 and SDRAM chip before modification]] |
|[[Image:Memory_Mod_Pic1.jpg|thumb|none|AV7110 and SDRAM chip before modification]] |
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In the above image you can see both chips as they are found on the card prior to any modification; with the AV7110 processor on the left and the, completely visible, 2MByte SDRAM memory chip on the right. The area conveyed in the image is roughly equivalent to that of the face of a 1EURO coin. |
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Here you can see both chips before the modification. |
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On the left hand side of the processor, the completely visible chip is the SDRAM memory chip. As a size comparison you see a 1EURO coin. |
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In performing the Mod, you will have to scratch one of the thin lines on the processor until the protective coating is removed, and then afterwards solder a thin wire on to it. Next, a second SDRAM chip has to be soldered on top of the existing one. For this step, you have to ''carefully'' bend the pins on the second SDRAM chip so that they all, except for pin 18, connect 1:1 to the first SDRAM chip's pins. The exception, pin 18 (the /ChipSelect), has to instead be connected to the thin wire that you soldered to the processor earlier in the modification process. After these steps have been completed, and provided that a [[Firmware]] cognizant of the additional memory is made available, the processor will then be able to use the full 4Mbytes now residing onboard the card. |
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For the Mod you have to scratch one of the thin lines on the processor until the protective coating is removed and solder a thin wire on it. |
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Then a second SDRAM chip has to be soldered on top of the existing one. For this you have to ''carefully'' bend the pins. Connect all pins 1:1 to the first SDRAM, except pin 18 (/ChipSelect). |
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This pin 18 has to be connected to the thin wire of the processor. |
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With extended [[Firmware]] the processor can use the full 4Mbytes. |
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{{Box Warning| |
{{Box Warning| |
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Revision as of 17:47, 4 January 2008
Memory Mod refers to upgrading a, so called, "full-featured" DVB card equipped with 2MByte SDRAM to 4MByte of SDRAM by means of placing another memory chip over an existing chip. The idea for this modification was introduced by Oliver Endriss.
The Idea
"Full-featured" DVB cards are equipped with a 2 MByte SDRAM chip. Using the Linux DVB drivers, OSD memory space is limited to approx. 80 KBytes. Therefore, it is not possible to have a full-screen, 256 color OSD when using VDR. However, the onboard AV7110/7111 MPEG2 Decoder used by these cards is able to handle/address two 2MByte SDRAM chips. Doubling the amount of addressable memory onboard these cards would effectively resolve the limitation outlined above and, hence, users could gain a full-screen 256 color OSD in VDR. Additionally there would be more space for the video buffers. Given the obvious benefit, why not add the second one?
The Modification
The chip select for the second SDRAM chip is not available on the pcb itself, so the AV7110 processor and the memory chip have to be modified.
In the above image you can see both chips as they are found on the card prior to any modification; with the AV7110 processor on the left and the, completely visible, 2MByte SDRAM memory chip on the right. The area conveyed in the image is roughly equivalent to that of the face of a 1EURO coin.
In performing the Mod, you will have to scratch one of the thin lines on the processor until the protective coating is removed, and then afterwards solder a thin wire on to it. Next, a second SDRAM chip has to be soldered on top of the existing one. For this step, you have to carefully bend the pins on the second SDRAM chip so that they all, except for pin 18, connect 1:1 to the first SDRAM chip's pins. The exception, pin 18 (the /ChipSelect), has to instead be connected to the thin wire that you soldered to the processor earlier in the modification process. After these steps have been completed, and provided that a Firmware cognizant of the additional memory is made available, the processor will then be able to use the full 4Mbytes now residing onboard the card.
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Warning !!! | |
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This modification is only for experienced people having knowledge and experience with SMD parts. It involves work with structures around 1/10 mm. Any failure may be risky for your DVB card! We take no responsibility for your card! |
Image of the modified DVB board:
- Step1: carefully bend the pins of the new sdram chip, i.e. by pressing the chip on a surface. You have to bend all pins except pin 18 CS (the 8th pin of the bottom lne, starting from the right). Have a look at the picture.
- Step2: solder the second SDRAM chip onto the top of the existing one. Solder the pins of the new chip on the pins of the old one. Ensure that you have all pins connected and no short circuits.
- Step3: carefully scratch through the protective coating of the AV7110 to get the coating removed from the wire. As you can see at the picture there are 6 round areas, the wire beneath the sixth with the small step is the one we need. Please do not scratch deeply as it would make it impossible to solder on that line. If you see the copper shining it's enough.
- Step4: soldering to the line
- Step5: Connect it to the pin 18 of the SDRAM. Use a very thin wire of approx 0.1mm diameter.
- Step6: Fix the thin wire and check the connection again
List of suitable SDRAM chips
This list may be imcomplete. The AV711x needs 3.3Volt IO-Ports, therefore a 3.3Volt SDRAM in TSOPII packaging is needed. Some of that chips are on old graphics boards.
| Producer | Part Name | Informations |
| ESMT/EliteMT | M12L16161A-7T | homepage datasheet |
| EtronTech | EM636165TS-8 | homepage datasheet |
| Samsung | K4S161622E-TC80 | homepage datasheet |
| Goldstar | GM72V161621 |
Software Requirements
DVB driver with 4MB support (Firmware 261c or newer)
Links
| [1] | vdrwiki:osdtest256-plugin | Plugin for testing of modded cards |
| [2] | vdrwiki:text2skin-plugin | plugin for loading of skins |
| [3] | http://www.rightchoiceelectronics.com/cr.html | Reference list with different ICs. Needed: 1Mx16 SDRAMs. |
| [4] | http://www.pcstats.com/ramfinder.cfm | RamFinder - Infos about RAM-ICs |
| [5] | http://www.wolfsoft.de | DVB Card Upgrade 2MB->4MB (~45 Euro) bzw. SDRAM (5,00+9,70)Euro |