The work deals with the design of a USB floppy drive driver. It describes the theory needed to design your own floppy drive driver and the output of individual components. The following is a schematic of the floppy drive driver design. The functions for controlling the floppy drive are described, as well as the pitfalls of the ATSAMD21J18A-AU processor used.

No description available.

Response time is one of the most important performance measures associated with a typical multi-user system. Response time, in turn, is bounded by the performance of the input/output (I/O) subsystem. Other than the end user and some external peripherals, the slowest component of the I/O subsystem is the disk drive. One standard strategy for improving I/O subsystem performance uses high-performance hardware like Small Computer Systems Interface (SCSI) drives to improve overall response time. SCSI hardware, unfortunately, is often too expensive to use in low-end multi-user systems. The low-end multi-user systems commonly use inexpensive Integrated Drive Electronics (IDE) disk drives to keep overall costs low. On such IDE based multi-user systems, reducing the Central Processing Unit (CPU) overhead associated with disk I/O is critical to system responsiveness. This thesis explores the impact of PCI bus mastering Direct Memory Access (DMA) on the performance of systems with IDE drives. DMA is a data transfer protocol that allows data to be sent directly from an attached device to a computer system’s main memory, thereby reducing CPU overhead. PCI bus mastering allows modern IDE disk controllers to manipulate main memory without utilizing motherboard-resident DMA controllers. Using a series of experiments, this thesis examines the impact of PCI bus mastering DMA on IDE performance for synchronous I/O, relative to Programmed Input/Output (PIO) and SCSI performance. Experiment results show that PCI bus mastering DMA, when used properly, improves the responsiveness and throughput of IDE drives by as much as a factor of seven. The magnitude of this improvement shows the importance of operating system support for DMA in low-end multi-user systems. Additionally, experimental results demonstrate that performance gains associated with SCSI are dependent on system usage and operating system support for advanced SCSI capabilities. Therefore, under many circumstances, high-performance SCSI drives are not cost effective when compared with IDE bus mastering DMA capable drives.

We present an on-disk sequence cache (ODSC), which improves disk drive performance. An ODSC uses a separate disk partition to store disk data in the order that the operating system requests it. Storing data in this order reduces the amount of seeking that the disk drive must do. As a result, the average disk access time is reduced. Reducing the disk access time improves the performance of the system, especially when booting the operating system, loading applications, and when main memory is limited. Experiments show that our ODSC speeds up application loads by as much as 413%. Our ODSC also reduces the disk access time of the Linux boot by 396%, and speeds up a Linux kernel make by 28%. We also show that an ODSC improves performance when main memory is limited.

Operational transconductance amplifier and capacitor (OTA-C) filters have outstood among different types of filter due to high frequency and low power capabilities in the main stream digital CMOS technology. They have been widely used in computer hard disk drive (HDD) and wireless communication transceivers. OTA-C filters based on cascade and passive ladder simulation are well-known. However, multiple loop feedback (MLF) OTA-C filters which have certain advantages still have the scope for further research. So far there have been no explicit formulas for current-mode leapfrog (LF) filter design and performance evaluation of current-mode MLF OTA-C filters are still lacking. From application viewpoints, read channels for computer hard disk drives require very high frequency continuous-time filters. This automatically disqualifies active- RC/MOSFET-C filters and OTA-C filters become the only solution. In wireless communications, active-RC/MOSFET-C filters have been proved useful for mobile systems whose baseband frequency falls below a few MHz. However, for wireless LANs with the frequency of several tens of MHz, OTA-C filters are a strong candidate. Whilst in HDD read channels, cascaded OTA-C architectures have been most utilized and in wireless receivers, OTA-C structures based on ladder simulation have been popular, MLF OTA-C filters have not been practically used in either of the applications. This thesis describes some novel designs and applications of multiple loop feedback OTA-C filters with extensive CMOS simulations. Analogue filters for computer hard disk drive systems are first reviewed; the state of the art and design considerations are provided. Three VHF linear phase lowpass OTA-C filters are then designed, which include a seventh-order and a fifth-order current-mode filter based on the follow-the-leader-feedback (FLF) structure and a seventh-order voltage-mode filter using the inverse FLF (IFLF) configuration. These filters all have very low power consumption. The synthesis and design of general current-mode LF OTA-C filters are conducted next. Iterative design formulas for both all-pole and finite-zero functions are derived and explicit formulas for up to sixth-orders are given. These formulas are very easy to use for designing any type of characteristics. Subsequently, linear phase lowpass OTA-C filter design for HDD read channels using LF structures are investigated in details. A current-mode filter and a voltage-mode filter using the fifth-order LF structure are presented. The two filters can operate up to 800MHz and have very small passband phase ripple. Analogue filters for wireless communication baseband applications are also reviewed thoroughly in this thesis, where the design of a fourth-order current-mode FLF Butterworth lowpass OTA-C filter for multi-standard receivers is presented. Then two fifth-order current-mode elliptic lowpass OTA-C filters based on respective LF and FLF structures for wireless communication baseband are designed. Fifth-order voltage-mode IFLF and LF elliptic lowpass filters are also presented. All these MLF baseband filters designed can operate up to 40MHz to cover all important wireless and mobile standards. Simulations show that the LF structures have better dynamic range and stopband attenuation performances than the FLF and IFLF configurations.

近年來大型消費性電子公司均致力發展商品外型的設計美感，試圖以具有視覺美感的商品吸引消費者的目光，以獲得更高的利潤。但本研究認為廠商在追逐商品設計美感時，也應探討消費者差異對於其美感反應的影響；以及不同商品以美感外型包裝時，對消費者的效果差異。對此，本研究以Bloch, Brunel & Arnold（2003）提出的消費者商品美感中心性（CVPA）、商品與自我一致性等概念，探討消費者對美感的心理差異，如何影響其對於商品設計美感的反應。同時並探討商品外顯性的差異，對於消費者的美感反應是否具有調節效果。 透過消費者美感中心性、商品設計美感、以及商品外顯性的2*2*2三因子實驗設計，本研究以3C商品為實驗商品，並以線上實驗的方式進行。研究結果如下： 1. 消費者重視美感的程度與商品設計美感間的一致性，會影響其對於商品設計的愉悅反應。 2. 商品呈現順序會調節不同CVPA消費者對於商品設計的愉悅、品牌興趣、自我與品牌連結、認知價值等反應。 3. 重視美感程度差異的消費者，並不會因為商品外顯性的調節而影響其美感反應。 4. 商品外顯性與商品設計美感之間具有交互效果：對於高外顯商品而言，高美感設計可有效提高消費者的認知價值，但低外顯商品若以高美感設計呈現，亦可使消費者因超乎預期的感受而倍感愉悅。 5. 消費者對於美感在認知層面的自我與品牌連結反應，會顯著受到CVPA「敏銳」面向的影響；在情感層面的美感評估、態度、愉悅等反應，則會顯著受到「價值」面向的影響；在行為層面的品牌興趣、購買意圖，則會顯著受到「反應」層面的影響。 / The role of aesthetical quality of a product has been placed much importance these years in the manufacturing industry, especially in consumer electronic industry. While developing products with aesthetical quality, it is also important to understand how consumers responded to products with high and low levels of aesthetic quality. The present study explored the moderating role of consumers’ psychological differences on their aesthetic responses, and also examined how differently they responded to products that differed on aesthetic quality and conspicuousness. This study adopted the concept of Centrality of Visual Product Aesthetics developed by Bloch, Brunel & Arnold (2003) and drew upon the concept of self-product image consistency to explore how consumers’ aesthetic orientation influence their responses to products with high and low aesthetic design. Moreover, the influence of product differences has also been considered. The proposed hypotheses were tested by a three-factor on-line experiment. The results are as follows: 1. The consistency of consumers’ CVPA and products’ design aesthetics influenced consumers’ pleasant feelings. 2. The order of how the stimuli were presented moderated the consistency effect mentioned above, especially on responses such as: pleasure, brand interest, self-brand connection, and perceived value toward the product. 3. For consumers with different levels of CVPA, the products’ conspicuousness did not moderate their aesthetic responses toward the product with high and low aesthetic designs. 4. There was an interaction between “product conspicuousness” and “product design aesthetics” on consumers’ “perceived value” and “pleasant feelings” toward product designs. 5. Consumers’ aesthetic responses were influenced by different dimensions of CVPA: “Acumen” accounted for significant variance in “self-brand connection,” “Value” explained significant variance in their attitudinal responses toward the product, and “Response” significantly predicted the variance in their behavioral responses. The implications and suggestions for future studies and practitioners were also discussed.

<p>Detta examensarbete reder ut arbetsprinciperna för olika typer av hårddiskskrivskydd; hårdvaruskrivskydd, mjukvaruskrivskydd, hybridskrivskydd och bygelskrivskydd. Slutsatsen av utredningen är att endast hårdvaruskrivskydd Detta examensarbete reder ut arbetsprinciperna för olika typer av hårddiskskrivskydd; hårdvaruskrivskydd, mjukvaruskrivskydd, hybridskrivskydd och bygelskrivskydd. Slutsatsen av utredningen är att endast hårdvaruskrivskydd bedöms ha tillräckligt pålitliga skyddsprinciper, vilket motiveras av dess oberoende från både hårdvara och operativsystem. </p><p>Vidare undersöks hårdvaruskrivskyddet Image MASSter(TM) Drive Lock från Intelligent Computer Solutions (ICS). Några egentliga slutsatser gick inte dra av kretskonstruktionen, bortsett från att den är uppbyggd kring en FPGA (Xilinx Spartan-II, XC2S15) med tillhörande PROM (XC17S15APC). </p><p>En egenutvecklad idé till autenticieringsmetod för hårddiskkloner föreslås som ett tillägg till arbetet. Principen bygger på att komplettera hårddiskklonen med unik information om hårddisk såväl kloningsomständigheter, vilka sammanflätas genom XOR-operation av komponenternas hashsummor.Autenticieringsmetoden kan vid sjösättning möjligen öka rättsäkerheten för både utredarna och den som står misstänkt vid en brottsutredning. </p><p>Arbetet är till stora delar utfört vid och på uppdrag av Statens kriminaltekniska laboratorium (SKL) i Linköping.</p>

Detta examensarbete reder ut arbetsprinciperna för olika typer av hårddiskskrivskydd; hårdvaruskrivskydd, mjukvaruskrivskydd, hybridskrivskydd och bygelskrivskydd. Slutsatsen av utredningen är att endast hårdvaruskrivskydd Detta examensarbete reder ut arbetsprinciperna för olika typer av hårddiskskrivskydd; hårdvaruskrivskydd, mjukvaruskrivskydd, hybridskrivskydd och bygelskrivskydd. Slutsatsen av utredningen är att endast hårdvaruskrivskydd bedöms ha tillräckligt pålitliga skyddsprinciper, vilket motiveras av dess oberoende från både hårdvara och operativsystem. Vidare undersöks hårdvaruskrivskyddet Image MASSter(TM) Drive Lock från Intelligent Computer Solutions (ICS). Några egentliga slutsatser gick inte dra av kretskonstruktionen, bortsett från att den är uppbyggd kring en FPGA (Xilinx Spartan-II, XC2S15) med tillhörande PROM (XC17S15APC). En egenutvecklad idé till autenticieringsmetod för hårddiskkloner föreslås som ett tillägg till arbetet. Principen bygger på att komplettera hårddiskklonen med unik information om hårddisk såväl kloningsomständigheter, vilka sammanflätas genom XOR-operation av komponenternas hashsummor.Autenticieringsmetoden kan vid sjösättning möjligen öka rättsäkerheten för både utredarna och den som står misstänkt vid en brottsutredning. Arbetet är till stora delar utfört vid och på uppdrag av Statens kriminaltekniska laboratorium (SKL) i Linköping.